View source for British Armed Forces

{{short description|Combined military forces of the United Kingdom}}
{{Redirect|His Majesty's Armed Forces|the military of Tonga|His Majesty's Armed Forces (Tonga)}}
{{Use British English|date=April 2015}}
{{Use dmy dates|date=February 2024}}
{{Infobox national military
| name = British Armed Forces
| image = [[File:MinistryofDefence.svg|frameless|upright=0.5]]
| caption = Badge of the [[Ministry of Defence (United Kingdom)|Ministry of Defence]]
| image2 = [[File:Flag of the Ministry of Defence (United Kingdom).svg|190px]]
| caption2 = [[List of United Kingdom flags#Combined Forces|Flag of the Ministry of Defence]]
| branches = {{tree list}}
* {{flagicon image|Naval Ensign of the United Kingdom.svg|size=23px}} [[His Majesty's Naval Service|HM Naval Service]]
** {{navy|United Kingdom}}
** {{marines|United Kingdom}}
* {{army|United Kingdom}}
* {{air force|United Kingdom}}
{{Tree list/end}}
| headquarters = [[Ministry of Defence Main Building|Ministry of Defence]], [[London]]
<!-- Leadership -->| commander-in-chief = {{Flagicon image|Royal standard of the United Kingdom.svg|size=25px}} [[Charles III|King Charles III]]
| commander-in-chief_title = [[Head of the Armed Forces]]
| chief minister = {{Flagicon image|Flag of the United Kingdom.svg|size=25px}} [[Keir Starmer|Sir Keir Starmer]]
| chief minister_title = [[Prime Minister of the United Kingdom|Prime Minister]]
| minister = {{Flagicon image|Flag of the British Secretary of State for Defence.svg|size=25px}} [[John Healey (politician)|John Healey]]
| minister_title = [[Secretary of State for Defence]]
| commander = {{Flagicon image|Flag of the Chief of the Defence Staff.svg|size=25px}} [[Air Chief Marshal]] [[Rich Knighton|Sir Rich Knighton]]
{{Infobox |child=yes
| label1 = [[Vice-Chief of the Defence Staff (United Kingdom)|Vice-Chief of the Defence Staff]]
| data1 =  {{Flagicon image|Flag of the United Kingdom.svg|size=25px}} [[General (United Kingdom)|General]] [[Sharon Nesmith|Dame Sharon Nesmith]]
| label2 = [[Senior Enlisted Advisor to the Chiefs of Staff Committee]]
| data2 =  {{Flagicon image|Flag of the United Kingdom.svg|size=25px}} [[Warrant officer (United Kingdom)|Warrant Officer Class 1]] Sarah Cox
}}
| commander_title = [[Chief of the Defence Staff (United Kingdom)|Chief of the Defence Staff]]
<!-- Manpower -->| age = {{nowrap|16–17 (with parental consent)}}<br/>18 (without and to serve in combat)
| conscription = No{{efn|[[National Service Act 1948|National Service]] ended in 1960, though periods of deferred service still had to be completed. The last national servicemen were discharged in 1963.}}<ref>{{cite web |title=National Service |url=https://www.parliament.uk/about/living-heritage/transformingsociety/private-lives/yourcountry/overview/nationalservice/ |website=UK Parliament |access-date=1 August 2021}}</ref>
| active = {{plainlist|
*136,117 regular forces personnel (January 2025)<ref name="stats">{{cite web|url=https://www.gov.uk/government/statistics/quarterly-service-personnel-statistics-2025/quarterly-service-personnel-statistics-1-january-2025#uk-service-personnel|title=Quarterly service personnel statistics 1 January 2025|publisher=Ministry of Defence|access-date=3 March 2025}}</ref>
* 4,127 [[Brigade of Gurkhas|Gurkhas]] (January 2025)<ref name="stats"/>
}}
| ranked = 
| reserve = 31,967 [[Volunteer Reserves (United Kingdom)|volunteer reserve]] personnel (January 2025)<ref name="stats"/>
| deployed = 
| amount = £62.0 billion <small>(2025/26)</small><ref>{{Cite web|url=https://commonslibrary.parliament.uk/research-briefings/cbp-8175/|title=UK defence spending|date=2025-05-28|accessdate=2025-07-26|language=en}}</ref><br>(~US$83.3 billion)
| percent_GDP = 2.33% (2024)<ref>{{Cite web |url=https://www.nato.int/nato_static_fl2014/assets/pdf/2024/6/pdf/240617-def-exp-2024-en.pdf#page=9/ |title=Defence Expenditure of NATO Countries (2014-2024) |publisher=nato.int|date=2024-06-17|accessdate=2024-06-18|language=en}}</ref>
<!-- Industrial -->| domestic_suppliers = * [[Babcock International]] 
* [[BAE Systems]]
* [[MBDA]]
* [[Qinetiq]]
* [[Rolls-Royce Holdings]]
* [[Serco]]
| foreign_suppliers = {{flag|United States}}<br>{{flag|Israel}}<br>{{flag|South Korea}}<br>{{flag|Germany}}<br>{{flag|France}}<br>{{flag|Netherlands}}<br>{{flag|Sweden}}<br>{{flag|Spain}}<br>{{flag|Finland}}<br>{{flag|Brazil}}<br>{{flag|Canada}}<br>{{flag|Norway}}
| imports = $568.1 million (2014–2022)<ref name="SIPRI_United Kingdom"/>
| exports = $1.074 billion (2014–2022)<ref name="SIPRI_United Kingdom">{{cite web|url=https://armstrade.sipri.org/armstrade/page/values.php|title=TIV of arms imports/exports data for United Kingdom, 2010-2021|date=7 February 2022|work=[[Stockholm International Peace Research Institute]]}}</ref>
<!-- Related articles -->| history = [[Military history of the United Kingdom]]<br />[[:Category:Wars involving the United Kingdom|Warfare directory of the United Kingdom]]<br />[[List of conflicts involving the United Kingdom|Conflicts involving the United Kingdom]]<br />[[:Category:Battles involving the United Kingdom|Battles involving the United Kingdom]]
| ranks = {{plainlist|
* '''Officer ranks'''
** [[Royal Navy officer rank insignia|Navy]]
** [[British Army officer rank insignia|Army]]
** [[RAF officer ranks|Air Force]]
* '''Other ranks'''
** [[Royal Navy other rank insignia|Navy]]
** [[British Army other ranks rank insignia|Army]]
** [[RAF other ranks|Air Force]]
}}
| founded = 1546 (Royal Navy)<br/>1660 (British Army)<br/>1918 (Royal Air Force)
}}

The '''British Armed Forces''' are the unified [[military|military forces]] responsible for the defence of the [[United Kingdom]], its [[British Overseas Territories|Overseas Territories]] and the [[Crown Dependencies]]. They also promote the UK's wider interests, support international [[peacekeeping]] efforts and provide [[humanitarian aid]].<ref>[http://www.armedforces.co.uk/mod/listings/l0002.html The Mission of the Armed Forces] {{Webarchive|url=https://web.archive.org/web/20070202073054/http://www.armedforces.co.uk/mod/listings/l0002.html |date=2 February 2007 }}, armedforces.co.uk</ref> The force is also known as '''His Majesty's Armed Forces.'''<ref>{{cite web |title=Armed Forces Day |url=https://armybenevolentfund.org/celebrations/armed-forces-day/ |website=Army Benevolent Fund |access-date=16 February 2025}}</ref><ref>{{cite web |title=Ancre Somme Association |url=https://www.asauk.org/armed-forces |website=www.asauk.org |publisher=Ancre Somme Association Charity |access-date=16 February 2025 |language=en}}</ref>

Since the formation of the united [[Kingdom of Great Britain]] in 1707 (later succeeded by the [[United Kingdom of Great Britain and Ireland]], and finally by the [[United Kingdom of Great Britain and Northern Ireland]]),<ref name=Union1707/> the British Armed Forces have seen action in most major wars involving the world's [[great power]]s, including the [[Seven Years' War]], the [[Napoleonic Wars]], the [[Crimean War]], the [[First World War]] and the [[Second World War]]. Britain's victories in most of these wars allowed it to influence world events and establish itself as one of the world's leading military and [[Economy|economic]] powers.<ref name=Johnston/> The British Armed Forces consist of: the [[Royal Navy]], a [[blue-water navy]] with a fleet of 62 commissioned and active ships, together with the [[Royal Marines]], a highly specialised amphibious light infantry force; the [[British Army]], the UK's principal [[land warfare]] branch; and the [[Royal Air Force]], a technologically sophisticated [[air force]] with a diverse operational fleet consisting of both fixed-wing and rotary aircraft. The British Armed Forces include standing forces, [[Regular Reserve (United Kingdom)|Regular Reserve]], [[Volunteer Reserves (United Kingdom)|Volunteer Reserves]] and [[Sponsored Reserves]].

[[King Charles III]], [[sovereign of the United Kingdom]], is the [[commander-in-chief]] and is styled as [[Head of the British Armed Forces|Head of the Armed Forces]],<ref name="Forces Queen and Armed Forces">[https://www.royal.uk/search?tags&#91;0&#93;=Queen%20and%20Armed%20 Forces Queen and Armed Forces] {{Webarchive|url=https://web.archive.org/web/20161022030320/https://www.royal.uk/search?tags%5B0%5D=Queen%20and%20Armed%20 |date=22 October 2016 }}, royal.uk.</ref><ref name="army.mod.uk">[https://www.army.mod.uk/news-and-events/news/2023/05/the-kings-long-links-to-the-army/], May 2023. Retrieved on 24 November 2023.</ref> with officers and personnel swearing [[allegiance]] to him. Long-standing constitutional convention, however, has vested ''de facto'' executive authority, by the exercise of [[Royal prerogative in the United Kingdom|royal prerogative]], in the [[Prime Minister of the United Kingdom|Prime Minister]] and the [[Secretary of State for Defence|secretary of state for defence]]. The Prime Minister (acting with the [[Cabinet of the United Kingdom|Cabinet]]) makes the key decisions on the use of the armed forces.<ref>[http://www.official-documents.gov.uk/document/cm71/7170/7170.pdf Governance of Britain], July 2007. Retrieved on 12 May 2013.</ref><ref>[http://webarchive.nationalarchives.gov.uk/20091111115352/http://www.justice.gov.uk/publications/docs/royal-prerogative.pdf Review of the Royal Prerogative Powers: Final Report], [[Ministry of Justice (United Kingdom)|Ministry of Justice]], October 2009. Retrieved on 12 May 2013.</ref> The [[UK Parliament]] approves the continued existence of the British Army by passing an [[Armed Forces Act]] at least once every five years, as required by the [[Bill of Rights 1689]]. Only a "standing army" requires reapproval by Parliament; the Royal Navy, Royal Air Force and the Royal Marines and any other forces are not included in the requirement. The armed forces are managed by the [[Defence Council of the United Kingdom|Defence Council]].

The United Kingdom is one of five [[Treaty on the Non-Proliferation of Nuclear Weapons|recognised nuclear powers]], a permanent member on the [[United Nations Security Council]], a founding and leading member of [[NATO]] and party to the [[AUKUS]] security pact and the [[Five Power Defence Arrangements]]. Overseas garrisons and training facilities are maintained at [[Ascension Island]], [[Bahrain]], [[Belize]], [[Bermuda]], [[British Indian Ocean Territory]], [[Brunei]], [[Canada]], [[Cyprus]], the [[Falkland Islands]], [[Germany]], [[Gibraltar]], [[Kenya]], [[Montserrat]], [[Nepal]], [[Qatar]], [[Singapore]] and the [[United States]].<ref name=europarl/> The British Armed Forces provided military training to approximately 140 countries in 2024–25.<ref>{{cite web |last=Pollard |first=Luke |author-link=Luke Pollard |title=Answer to: Military Aid, Question for Ministry of Defence, UIN 60404, tabled on 16 June 2025 |website=[[Parliament of the United Kingdom]] |date=24 June 2025 |access-date=23 August 2025 |url=https://questions-statements.parliament.uk/written-questions/detail/2025-06-16/60404 |archive-url=https://web.archive.org/web/20250823204259/https://questions-statements.parliament.uk/written-questions/detail/2025-06-16/60404 |archive-date=23 August 2025 |url-status=live}}</ref>

==History==
{{Main|History of the Royal Navy|History of the British Army|History of the Royal Air Force}}
[[File:Ourworldindata uk-defence-spending-as-a-percentage-of-gdp.png|thumb|Defence spending in the UK]]

===Organisation===
With the [[Acts of Union 1707]], the armed forces of England and Scotland were merged into the armed forces of the [[Kingdom of Great Britain]].<ref name=Union1707>[http://www.parliament.uk/about/living-heritage/evolutionofparliament/legislativescrutiny/ Acts of Union 1707] {{Webarchive|url=https://web.archive.org/web/20120529130147/http://www.parliament.uk/about/living-heritage/evolutionofparliament/legislativescrutiny/ |date=29 May 2012 }} parliament.uk, accessed 31 December 2010; [http://www.nationalarchives.gov.uk/pathways/citizenship/rise_parliament/uniting.htm Uniting the kingdom?] {{Webarchive|url=https://web.archive.org/web/20160308174527/http://www.nationalarchives.gov.uk/pathways/citizenship/rise_parliament/uniting.htm |date=8 March 2016 }} nationalarchives.gov.uk, accessed 31 December 2010; [http://www.scottish.parliament.uk/vli/visitingHolyrood/union_exhibition.pdf Making the Act of Union 1707] {{Webarchive|url=https://web.archive.org/web/20110511140052/http://www.scottish.parliament.uk/vli/visitingHolyrood/union_exhibition.pdf |date=11 May 2011 }} scottish.parliament.uk, accessed 31 December 2010</ref>

There were originally several naval and several military regular and reserve ''forces'', although most of these were consolidated into the Royal Navy or the British Army during the 19th and 20th Centuries (the [[Royal Naval Air Service]] and the [[Royal Flying Corps]] of the British Army, by contrast, were separated from their parent forces in 1918 and amalgamated to form a new force, the [[Royal Air Force]], which would have complete responsibility for naval, military and strategic aviation until the [[Second World War]]).

Naval forces included the [[Royal Navy]], the [[Waterguard]], later renamed the [[HM Coastguard]], and [[Sea Fencibles]] and ''River Fencibles'' formed as and when required for the duration of emergencies. The [[Merchant Navy]] and offshore fishing boat crews were also important manpower reserves to the armed naval forces. Any seaman was liable to [[impressment]], with many so conscripted especially during the two decades of conflict from the French Revolution until the end of the Napoleonic Wars, and from 1835 registered on the ''Register of Seamen'' to identify them as a potential resource, and many of their seamen would serve part time in the [[Royal Navy Reserve]], created under the Naval Reserve Act 1859, and [[Royal Naval Volunteer Reserve]], created in 1903.

The British military (those parts of the British Armed Forces tasked with land warfare, as opposed to the naval forces)<ref>{{citation |url=https://api.parliament.uk/historic-hansard/commons/1917/feb/12/naval-and-military-pensions-and-grants |title=NAVAL AND MILITARY PENSIONS AND GRANTS |work=[[Hansard|Parliamentary Debates (Hansard)]] |date=12 February 1917 |volume=90 |at=cc248-51 |access-date=8 June 2021 |archive-date=21 May 2022 |archive-url=https://web.archive.org/web/20220521061200/http://hansard.millbanksystems.com/commons/1917/feb/12/naval-and-military-pensions-and-grants |url-status=live }}</ref> historically was divided into a number of [[Units of the British Army#Forces|military forces]], of which the British Army (also referred to historically as the 'Regular Army' and the 'Regular Force') was only one.<ref>''A LIST OF THE OFFICERS of the ARMY, (WITH AN ALPHABETICAL INDEX;) OF THE OFFICERS of the ROYAL ARTILLERY, THE ENGINEERS, the MARINE FORCES, AND OF THE OFFICERS on HALF-PAY; AND A SUCCESSION of COLONELS. THE THIRTY-SECOND EDITION''. War-Office. 31 March 1784</ref><ref>{{citation |title=THE NEW ANNUAL ARMY LIST, MILITIA LIST |date= 1854 <!--: (BEING THE FIFTEENTH ANNUAL VOLUME), CONTAINING THE DATES OF COMMISSIONS, AND A STATEMENT OF THE WAR SERVICES AND WOUNDS OF NEARLY EVERY OFFICER IN THE ARMY, ORDNANCE, AND MARINES. CORRECTED TO 30th December 1853 . WITH AN INDEX''. --> |author=Major H. G. Hart, 49TH REGT |publisher=John Murray |location=London}}</ref> The oldest of these organisations was the [[Militia (Great Britain)|Militia Force]] (also referred to as the ''Constitutional Force''),<ref>{{Cite web |url=https://api.parliament.uk/historic-hansard/commons/1852/apr/23/militia-bill |title=''MILITIA BILL''. House of Commons Debate 23 April 1852. Volume 120 cc1035-109. British Parliament website |access-date=8 June 2021 |archive-date=24 May 2022 |archive-url=https://web.archive.org/web/20220524093720/http://hansard.millbanksystems.com/commons/1852/apr/23/militia-bill |work=[[Hansard|Parliamentary Debates (Hansard)]] |date=23 April 1852 |url-status=live }}</ref><ref>{{Cite web |url=https://api.parliament.uk/historic-hansard/commons/1855/may/04/the-militia |title=''THE MILITIA''. House of Commons Debate 4 May 1855. Volume 138 cc116-32. British Parliament website |access-date=8 June 2021 |archive-date=25 April 2022 |archive-url=https://web.archive.org/web/20220425093514/http://hansard.millbanksystems.com/commons/1855/may/04/the-militia |work=[[Hansard|Parliamentary Debates (Hansard)]] |date=4 May 1855 |url-status=live }}</ref><ref>{{Cite web |url=https://api.parliament.uk/historic-hansard/lords/1856/jul/11/the-militia-question |title=''THE MILITIA—QUESTION''. House of Lords Debate 11 July 1856. Volume 143 cc625-32. British Parliament website |access-date=8 June 2021 |archive-date=9 March 2017 |archive-url=https://web.archive.org/web/20170309065917/https://hansard.millbanksystems.com/lords/1856/jul/11/the-militia-question |work=[[Hansard|Parliamentary Debates (Hansard)]] |date=11 July 1856 |url-status=live }}</ref><ref>{{Cite web |url=https://api.parliament.uk/historic-hansard/commons/1878/jun/13/army-auxiliary-forces-the-militia |title=''ARMY—AUXILIARY FORCES—THE MILITIA.—OBSERVATIONS''. House of Commons Debate 13 June 1878. Volume 240 cc1418-33. British Parliament website |access-date=8 June 2021 |archive-date=23 May 2022 |archive-url=https://web.archive.org/web/20220523113730/http://hansard.millbanksystems.com/commons/1878/jun/13/army-auxiliary-forces-the-militia |work=[[Hansard|Parliamentary Debates (Hansard)]] |date=13 June 1878 |url-status=live }}</ref> which (in the [[Kingdom of England]]) was originally the main military defensive force (there otherwise were originally only royal bodyguards, including the [[Yeomen Warders]] and the [[Yeomen of the Guard]], with armies raised only temporarily for expeditions overseas), made up of civilians embodied for annual training or emergencies, and had used various schemes of compulsory service during different periods of its long existence.

The Militia was originally an all infantry force, organised at the city or county level, and members were not required to serve outside of their recruitment area, although the area within which militia units in Britain could be posted was increased to anywhere in the Britain during the 18th century, and [[Militia Artillery units of the United Kingdom and Colonies|Militia coastal artillery]], field artillery, and engineers units were introduced from the 1850s.<ref name="norman1987">''The Militia Artillery 1852-1909'', by Norman EH Litchfield. The Sherwood Press (Nottingham) Ltd. 1987</ref> The [[Yeomanry]] was a mounted force that could be mobilised in times of war or emergency.<ref>{{Cite web |url=https://api.parliament.uk/historic-hansard/lords/1903/may/26/an-imperial-yeomanry-reserve |title=''AN IMPERIAL YEOMANRY RESERVE''. House of Lords Debate 26 May 1903. Vol 122 cc1767-71. British Parliament website |access-date=8 June 2021 |archive-date=16 August 2021 |archive-url=https://web.archive.org/web/20210816133114/http://hansard.millbanksystems.com/lords/1903/may/26/an-imperial-yeomanry-reserve |work=[[Hansard|Parliamentary Debates (Hansard)]] |date=26 May 1903 |url-status=live }}</ref> [[Volunteer Force]] units were also frequently raised during wartime, which did not rely on compulsory service and hence attracted recruits keen to avoid the Militia. These were seen as a useful way to add to military strength economically during wartime, but otherwise as a drain on the Militia and so were not normally maintained in peacetime, although in Bermuda prominent propertied men were still appointed ''Captains of Forts'', taking charge of maintaining and commanding fortified [[coastal artillery]] batteries and manned by volunteers (reinforced in wartime by embodied militiamen), defending the colony's coast from the 17th century to the 19th century (when all of the batteries were taken over by the regular Royal Artillery).<ref>''Bermuda Forts 1612–1957'', Dr. Edward Cecil Harris, The Bermuda Maritime Museum Press, {{ISBN|0-921560-11-7}}</ref><ref>''Bulwark Of Empire: Bermuda's Fortified Naval Base 1860–1920'', Lt.-Col. Roger Willock, USMC, The Bermuda Maritime Museum Press, The Bermuda Maritime Museum. {{ISBN|978-0-921560-00-5}}</ref> The militia system was extended to a number of English (subsequently ''British'') colonies, beginning with [[Colony of Virginia|Virginia]] and [[Bermuda]]. In some colonies, ''Troops of Horse'' or other mounted units similar to the Yeomanry were also created.<ref>{{Cite web |url=http://www.bermudastamps.co.uk/1988/11/10/military-uniforms-bermuda |title=''1988 Military Uniforms of Bermuda'', By Neil Rigby on November 10, 1988 in First Day Covers, Queen Elizabeth II. Bermuda Stamps website |access-date=8 June 2021 |archive-date=23 April 2021 |archive-url=https://web.archive.org/web/20210423020210/http://www.bermudastamps.co.uk/1988/11/10/military-uniforms-bermuda/ |url-status=dead }}</ref> The militia and volunteer units of a colony were generally considered to be separate forces from the ''Home'' Militia Force and Volunteer Force in the United Kingdom, and from the militia forces and volunteer forces of other colonies. Where a colony had more than one militia or volunteer unit, they would be grouped as a militia or volunteer force for that colony, such as the Jamaica Volunteer Defence Force, which comprised the St. Andrew Rifle Corps, or Kingston Infantry Volunteers, the Jamaica Corps of Scouts, and the Jamaica Reserve Regiment,<ref>[https://www.jdfweb.com/third-battalion-duties/ ''Jamaica Defence Force: Third Battalion Duties''. Jamaica Defence Force website]</ref> but not the [[Jamaica Militia Artillery]].<ref>{{Cite web |url=https://livelb.nationalarchives.gov.uk/first-world-war/a-global-view/the-caribbean/jamaica/ |title=''Jamaica in 1914: War effort'' The National Archives, Kew |access-date=8 June 2021 |archive-date=8 June 2021 |archive-url=https://web.archive.org/web/20210608121902/https://livelb.nationalarchives.gov.uk/first-world-war/a-global-view/the-caribbean/jamaica/ |url-status=dead }}</ref> In smaller colonies with a single militia or volunteer unit, that single unit would still be considered to be listed within a force, or in some case might be named a force rather than a regiment or corps, such as is the case for the [[Falkland Islands Defence Force]] and the [[Royal Montserrat Defence Force]]. The militia, yeomanry and volunteer forces collectively were known as the ''reserve forces'', ''auxiliary forces'', or ''local forces''. Officers of these forces could not sit on courts martial of regular forces personnel. The [[Mutiny Act]] did not apply to members of the Reserve Forces.

The other regular military force that existed alongside the British Army was the [[Board of Ordnance]], which included the ''Ordnance Military Corps'' (made up of the Royal Artillery, Royal Engineers, and the Royal Sappers and Miners), as well as the originally-civilian [[Commissariat#19th century|Commissariat Stores]] and transport departments, as well as barracks departments, ordnance factories and various other functions supporting the various naval and military forces.<ref>{{Cite web |url=https://www.forces-war-records.co.uk/units/3224/department-of-the-master-general-of-the-ordnance |title=''Unit History: Department of the Master-General of the Ordnance''. Forces War Records |access-date=8 June 2021 |archive-date=5 October 2021 |archive-url=https://web.archive.org/web/20211005123115/https://www.forces-war-records.co.uk/units/3224/department-of-the-master-general-of-the-ordnance |url-status=dead }}</ref><ref>{{usurped|1=[https://web.archive.org/web/20210511140506/https://www.navalhistoryarchive.org/index.php/Board_of_Ordnance ''Board of Ordnance''. Naval History Archive]}}</ref> The English Army, subsequently the British Army once Scottish regiments were moved onto its establishment following the Union of the Kingdoms of Scotland and England, was originally a separate force from these, but absorbed the Ordnance Military Corps and various previously civilian departments after the Board of Ordnance was abolished in 1855.<ref>{{cite journal | url=https://www.jstor.org/stable/44220102 | jstor=44220102 | title=The Honorable the Board of Ordnance. 1299—1855 | last1=Leslie | first1=J. H. | journal=Journal of the Society for Army Historical Research | date=1925 | volume=4 | issue=17 | pages=100–104 }}</ref><ref>[https://www.nam.ac.uk/explore/corps-royal-engineers ''Corps of Royal Engineers''. National Army Museum]</ref> The ''Reserve Forces'' (which referred to the Home Yeomanry, Militia and Volunteer Forces before the 1859 creation of the [[Regular Reserve (United Kingdom)#Army Reserve (Regular)|British Army ''Regular Reserve'']] by [[Secretary of State for War]] [[Sidney Herbert, 1st Baron Herbert of Lea|Sidney Herbert]], and re-organised under the [[Reserve Force Act 1867]])<ref>''The Army Book For The British Empire'', by Lieutenant-General WH Goodenough, Royal Artillery, CB, and Lieutenant-Colonel JC Dalton (HP), Royal Artillery, Her Majesty's Stationery Office, London. 1893.</ref> were increasingly integrated with the British Army through a succession of reforms over the last two decades of the 19th century (in 1871, command of the Auxiliary Forces in the British Isles was taken from the [[Lord-Lieutenant|Lords-Lieutenant of counties]] and transferred to the [[War Office]], though colonial governors retained control of their militia and volunteer forces, and by the end of the century, at the latest, any unit wholly or partly funded from Army funds was considered part of the British Army) and the early years of the 20th century,<ref>{{Cite web |url=https://api.parliament.uk/historic-hansard/commons/1895/mar/15/the-army-estimates |title=''THE ARMY ESTIMATES''. House of Commons Debate 15 March 1895. Vol 31 cc1157-209. British Parliament website |access-date=8 June 2021 |archive-date=18 August 2021 |archive-url=https://web.archive.org/web/20210818023526/http://hansard.millbanksystems.com/commons/1895/mar/15/the-army-estimates |work=[[Hansard|Parliamentary Debates (Hansard)]] |date=15 March 1895 |url-status=live }}</ref> whereby the Reserve Forces units mostly lost their own identities and became numbered [[Territorial Force]] sub-units of regular British Army corps or regiments (the Home Militia had followed this path, with the Militia Infantry units becoming numbered battalions of British Army regiments, and the Militia Artillery integrating within Royal Artillery territorial divisions in 1882 and 1889, and becoming parts of the [[Royal Field Artillery]] or [[Royal Garrison Artillery]] in 1902 (though retaining their traditional corps names), but was not merged into the Territorial Force when it was created in 1908 (by the merger of the Yeomanry and Volunteer Force). The Militia was instead renamed the ''Special Reserve'',<ref>''Hart's Annual Army List, Special Reserve List, and Territorial Force List, for 1911: (Being the Seventy-Second Annual Volume,) Containing Dates of Commissions, and a Summary of the War Services of Nearly Every Officer in the Army, Supply &c. Departments, Marines, and Indian Army, and Indian Local Forces. With an Index.'' By the late Lieutenant general H. G. Hart. John Murray, Albemarle Street, London. 1911</ref><ref>{{Cite web |url=https://api.parliament.uk/historic-hansard/lords/1908/feb/18/the-territorial-forces-act-the-militia |title=''THE TERRITORIAL FORCES ACT—THE MILITIA''. House of Lords Debate 18 February 1908. Volume 184 cc578-605. British Parliament website |access-date=8 June 2021 |archive-date=8 March 2017 |archive-url=https://web.archive.org/web/20170308220253/https://hansard.millbanksystems.com/lords/1908/feb/18/the-territorial-forces-act-the-militia |work=[[Hansard|Parliamentary Debates (Hansard)]] |date=18 February 1908 |url-status=live }}</ref><ref>{{Cite web |url=https://api.parliament.uk/historic-hansard/written-answers/1913/apr/09/british-army-home-and-colonial-military |title=''BRITISH ARMY.—HOME AND COLONIAL MILITARY FORCES''. House of Commons Debate 9 April 1913. Volume 51 cc1196-8W. British Parliament website |access-date=8 June 2021 |archive-date=18 August 2021 |archive-url=https://web.archive.org/web/20210818113804/http://hansard.millbanksystems.com/written_answers/1913/apr/09/british-army-home-and-colonial-military |work=[[Hansard|Parliamentary Debates (Hansard)]] |date=9 April 1913 |url-status=live }}</ref> and was permanently suspended after the First World War (although a handful of Militia units survived in the United Kingdom, its colonies, and the Crown Dependencies). Unlike the Home, Imperial Fortress and Crown Dependency Militia and Volunteer units and forces that continued to exist after the First World War, although parts of the British military, most were not considered parts of the [[British Army]]<ref>[https://www.stabroeknews.com/2008/10/01/guyana-review/the-british-guiana-volunteer-force ''The British Guiana Volunteer Force''. Stabroek News. 1 October, 2008]</ref><ref>{{Cite web |url=https://www.colonialforces.org/batteries-companies-regiments-and-c |title=''Batteries, Companies, Regiments and Corps (Land): Defending the colony'', Colonial Forces Study Group (Queensland) Inc |access-date=8 June 2021 |archive-date=27 January 2021 |archive-url=https://web.archive.org/web/20210127130254/https://www.colonialforces.org/batteries-companies-regiments-and-c |url-status=usurped }}</ref> unless they received Army funds, as was the case for the [[Bermuda Militia Artillery]] and the [[Bermuda Volunteer Rifle Corps]],<ref>''History of The Coast Artillery in the British Army'', by Colonel KW Maurice-Jones, DSO, RA. Royal Artillery Institution. 1959</ref><ref name="norman1987" /> which was generally only the case for those in the Channel Islands or the Imperial Fortress colonies (Nova Scotia, before [[Canadian Confederation]], Bermuda, Gibraltar, and Malta).<ref>{{Cite web |url=https://livelb.nationalarchives.gov.uk/first-world-war/a-global-view/the-caribbean/bermuda |title=''Bermuda in 1914'' The National Archives, Kew |access-date=8 June 2021 |archive-date=17 June 2021 |archive-url=https://web.archive.org/web/20210617014624/https://livelb.nationalarchives.gov.uk/first-world-war/a-global-view/the-caribbean/bermuda/ |url-status=dead }}</ref><ref>''The Quarterly Army List''  Part I, January 1945. Order of Precedence of the British Army. Page xiii. His Majesty's Stationery Office</ref><ref>{{Cite web |url=https://api.parliament.uk/historic-hansard/commons/1899/mar/17/army-estimates-1899-1900#division_48 |title=''ARMY ESTIMATES, 1899–1900''. House of Commons Debate 17 March 1899. Vol 68 cc1161-287 British Parliament website |access-date=8 June 2021 |archive-date=16 August 2021 |archive-url=https://web.archive.org/web/20210816203541/http://hansard.millbanksystems.com/commons/1899/mar/17/army-estimates-1899-1900/division_48 |work=[[Hansard|Parliamentary Debates (Hansard)]] |date=17 March 1899 |url-status=live }}</ref> Today, the British Army is the only Home British military force (unless the [[Army Cadet Force]] and the [[Combined Cadet Force]] are considered), including both the regular army and the forces it absorbed, though British military units organised on Territorial lines remain in British Overseas Territories that are still not considered formally part of the British Army, with only the [[Royal Gibraltar Regiment]] and the [[Royal Bermuda Regiment]] (an amalgam of the old Bermuda Militia Artillery and Bermuda Volunteer Rifle Corps) appearing on the British Army order of precedence and in the Army List.

Confusingly, and similarly to the dual meaning of the word [[Corps#United Kingdom|Corps]] in the British Army. As an example, the 1st Battalion of the [[King's Royal Rifle Corps]] was in 1914 part of the 6th Brigade that was part of the [[2nd Infantry Division (United Kingdom)|2nd Infantry Division]], which was itself part of [[I Corps (United Kingdom)|1st Army Corps]]), the British Army sometimes also used the term [[Expeditionary warfare|expeditionary force]] or [[field force]] to describe a body made up of British Army units, most notably the [[British Expeditionary Force (World War I)|British Expeditionary Force]], or of a mixture of British Army, Indian Army, or Imperial auxiliary units, such as the [[Siege of Malakand#Malakand Field Force|Malakand Field Force]] (this is similarly to the naval use of the term [[task force]]). In this usage, ''force'' is used to describe a self-reliant body able to act without external support, at least within the parameters of the task or objective for which it is employed.

===British Empire===
[[File:Battle of Trafalgar Poster 1805.jpg|thumb|A modern reproduction of an 1805 poster commemorating the [[Battle of Trafalgar]]]]

During the later half of the 17th century, and in particular, throughout the 18th century, British foreign policy sought to contain the expansion of rival European powers through military, diplomatic and commercial means, especially of its chief competitors [[Spain]], the [[Netherlands]], and [[France]]. This saw Britain engage in a number of intense conflicts over colonial possessions and world trade, including a long string of Anglo-Spanish and Anglo-Dutch wars, as well as a series of "world wars" with France, such as; the [[Seven Years' War]] (1756–1763), the [[French Revolutionary Wars]] (1792–1802) and the [[Napoleonic Wars]] (1803–1815). During the Napoleonic wars, the Royal Navy victory at [[Battle of Trafalgar|Trafalgar]] (1805) under the command of [[Horatio Nelson, 1st Viscount Nelson|Horatio Nelson]] (aboard [[HMS Victory|HMS ''Victory'']]) marked the culmination of British maritime supremacy, and left the Navy in a position of uncontested hegemony at sea.<ref>Nelson's Navy: The Ships, Men, and Organization, 1793-1815Brian Lavery</ref> By 1815 and the conclusion of the Napoleonic Wars, Britain had risen to become the world's dominant [[great power]] and the [[British Empire]] subsequently presided over a period of relative peace, known as [[Pax Britannica]].<ref name=Johnston>{{cite book|last1=Johnston|first1=Douglas M.|last2=Reisman|first2=W. Michael|title=The Historical Foundations of World Order|date=2008|publisher=Martinus Nijhoff Publishers|location=Leiden|isbn=978-9047423935|url=https://books.google.com/books?id=dVuwCQAAQBAJ&pg=PA508|ref=refJohnston2008}}, pp.&nbsp;508–10.</ref><ref>[[Brison D. Gooch]], ''Recent Literature on Queen Victoria's Little Wars'' ''Victorian Studies,'' 17#2 (1973): 217-224 [https://www.jstor.org/stable/3826186 online].</ref>

With Britain's old rivals no-longer a threat, the 19th century saw the emergence of a new rival, the [[Russian Empire]], and a strategic competition in what became known as [[The Great Game]] for supremacy in [[Central Asia]].<ref name=keay419>{{cite book|last=Keay|first=John|title=India: A History|year=2010|publisher=Grove Press|location=New York, NY|isbn=978-0-8021-4558-1|edition=revised|author-link=John Keay|pages=418–9}}</ref> Britain feared that Russian expansionism in the region would eventually threaten the [[British Raj|Empire]] in India.<ref name=keay419/> In response, Britain undertook a number of pre-emptive actions against perceived Russian ambitions, including the [[First Anglo-Afghan War]] (1839–1842), the [[Second Anglo-Afghan War]] (1878–1880)<ref name=Schmidt>{{cite book|last=Schmidt|first=Karl J.|title=An Atlas and Survey of South Asian History|year=1995|publisher=M.E. Sharpe|isbn=978-1563243332|page=[https://archive.org/details/atlassurveyofsou0000schm/page/74 74]|url-access=registration|url=https://archive.org/details/atlassurveyofsou0000schm/page/74}}</ref> and the [[British expedition to Tibet]] (1903–1904). During this period, Britain also sought to maintain the [[Balance of power (international relations)|balance of power]] in Europe, particularly against Russian expansionism,<ref>{{cite journal | last1 = Hew Strachan | first1 = Hew | year = 1978 | title = Soldiers, Strategy and Sebastopol | journal = Historical Journal | volume = 21 | issue = 2| pages = 303–325 | doi=10.1017/s0018246x00000558 | jstor=2638262| s2cid = 154085359 }}</ref> who at the expense of the waning [[Ottoman Empire]] had ambitions to "carve up the European part of Turkey".<ref name=ALambert>{{cite web|last1=Lambert|first1=Andrew|title=The Crimean War|url=https://www.bbc.co.uk/history/british/victorians/crimea_01.shtml|website=The BBC - History|publisher=The BBC|access-date=21 January 2016|archive-url=https://web.archive.org/web/20151210171630/http://www.bbc.co.uk/history/british/victorians/crimea_01.shtml|archive-date=10 December 2015|url-status=live}}</ref> This ultimately led to British involvement in the [[Crimean War]] (1854–1856) against the Russian Empire.<ref name=ALambert/>

[[File:Royal Irish Rifles ration party Somme July 1916.jpg|thumb|[[Royal Irish Rifles]] soldiers at the [[Battle of the Somme]] in 1916]]

===First World War===
The beginning of the 20th century served to [[Anglo-Russian Entente|reduce tensions]] between Britain and the Russian Empire, partly due to the emergence of a unified [[German Empire]]. The era brought about an [[Anglo-German naval arms race]], which encouraged significant advancements in maritime technology, including [[Dreadnought]]s, [[torpedo]]es, [[submarine]]s), and, in 1906, Britain determined that its only likely naval enemy was Germany.<ref>Herwig p. 48–50</ref> The [[Causes of World War I|accumulated tensions]] in European relations finally broke out into the hostilities of the [[First World War]] (1914–1918), in what is recognised today, as the most devastating war in British military history, with nearly 800,000 men killed and over 2&nbsp;million wounded.<ref>{{citation |last=Willmott |first=H.P. |year=2003 |title=World War I |location=New York |publisher=Dorling Kindersley |isbn=978-0-7894-9627-0 |oclc=52541937}}</ref> [[Allies of World War I|Allied]] victory resulted in the defeat of the [[Central Powers]], the end of the German Empire, the [[Treaty of Versailles]] and the establishment of the [[League of Nations]].

===Second World War===
[[File:No. 4 Commando 22 April 1942.jpg|thumb|British commandos during the Second World War]]
Germany was defeated in the First World War, but by 1933 [[fascism]] had given rise to [[Nazi Germany]], which under the leadership of [[Adolf Hitler]] re-militarised in defiance of the Treaty of Versailles. Once again [[Causes of World War II|tensions accumulated]] in European relations, and following Germany's [[invasion of Poland]] in September 1939, the [[Second World War]] began (1939–1945).<ref>{{cite book|last=Mallinson |first=Allan |year=2009 |title=The Making of the British Army |publisher=Bantam Press |isbn=978-0-593-05108-5}}</ref> The conflict was the most widespread in British history, with British Empire and [[Commonwealth of Nations|Commonwealth]] troops engaged in military campaigns in Europe, [[North Africa]], the [[Middle East]], and the [[Far East]]. Approximately 390,000 British Empire and Commonwealth troops died.<ref>{{cite web|title=Commonwealth War Graves Commission Annual Report 2014–2015 p. 38|url=https://issuu.com/wargravescommission/docs/ar_2014-2015?e=4065448/31764375|website=Commonwealth War Graves Commission|access-date=1 July 2016|archive-url=https://web.archive.org/web/20160625000629/https://issuu.com/wargravescommission/docs/ar_2014-2015?e=4065448%2F31764375|archive-date=25 June 2016|url-status=live}}</ref> [[Allies of World War II|Allied]] victory resulted in the defeat of the [[Axis powers]] and the establishment of the [[United Nations]], replacing the League of nations.

===Cold War===
{{Main|Outline of the British Armed Forces at the end of the Cold War}}
[[File:Avro Vulcan Bomber RAF.JPEG|thumb|The [[Vulcan Bomber]] was the mainstay of Britain's airborne nuclear capability for much of the [[Cold War]].]]
Post–Second World War economic and political decline, as well as changing attitudes in British society and government, were reflected by the armed forces' contracting global role,<ref>Colman (2005), ''A 'Special Relationship'?: Harold Wilson, Lyndon B. Johnson, and Anglo-American Relations' at the Summit', 1964–68'', p77</ref><ref name="Focus on Euope">[http://www.raf.mod.uk/rafcms/mediafiles/F21E81DC_E902_D3CE_488720FE8488434D.pdf Focus on Europe] {{Webarchive|url=https://web.archive.org/web/20070222004546/http://www.raf.mod.uk/rafcms/mediafiles/F21E81DC_E902_D3CE_488720FE8488434D.pdf |date=22 February 2007 }}, raf.mod.uk</ref> and later epitomised by its political defeat during the [[Suez Crisis]] (1956).<ref>Johnman & Gorst (1997), ''The Suez Crisis'', p166</ref> Reflecting [[British Empire#Decolonisation and decline (1945–1997)|Britain's new role in the world]] and the escalation of the [[Cold War]] (1947–1991), the country became a founding member of the [[NATO]] military alliance in 1949. [[Defence Review]]s, such as those in [[1957 Defence White Paper|1957]] and [[1966 Defence White Paper|1966]], announced significant reductions in conventional forces,<ref>Lider (1985), ''British Military Thought After World War II'', p525</ref> the pursuement of a doctrine based on [[nuclear deterrence]],<ref>Lee (1996), ''Aspects of British Political History 1914–1995'', 273</ref><ref>Pierre (1972), ''Nuclear Politics: the British experience with an independent strategic force: 1939–1970'', p100</ref> and a permanent military withdrawal [[east of Suez]].<ref>Hack (2000), ''Defence and Decolonisation in South-East Asia: Britain, Malaya, Singapore, 1941–1968'', p285</ref><ref>Chandler & Beckett (2003), p345</ref> By the mid-1970s, the armed forces had reconfigured to focus on the responsibilities allocated to them by NATO.<ref name="Focus on Euope" /><ref name="Navy-45-2000">[http://www.royal-navy.mod.uk/server/show/nav.3867 Vanguard to Trident 1945–2000] {{webarchive|url=https://web.archive.org/web/20070310224429/http://www.royal-navy.mod.uk/server/show/nav.3867 |date=10 March 2007 }}, royal-navy.mod.uk</ref><ref name=autogenerated2>Kennedy (2004), ''British Naval Strategy East of Suez, 1900–2000: Influence and Actions'', p193</ref> The [[British Army of the Rhine]] and [[RAF Germany]] consequently represented the largest and most important overseas commitments that the armed forces had during this period,<ref>Chandler & Beckett (2003), p421</ref> while the Royal Navy developed an [[anti-submarine warfare]] specialisation, with a particular focus on countering [[Soviet Union|Soviet]] submarines in the Eastern Atlantic and [[North Sea]].<ref name="Navy-45-2000" />

While NATO obligations took increased prominence, Britain nonetheless found itself engaged in a number of low-intensity conflicts, including a spate of insurgencies against colonial occupation.<ref name="Insurgencies">Chandler & Beckett (2003), pp350–351</ref> However the [[Dhofar Rebellion]] (1962–1976) and [[The Troubles]] (1969–1998) emerged as the primary operational concerns of the armed forces.<ref name="Insurgencies"/> Perhaps the most important conflict during the Cold War, at least in the context of British defence policy, was the [[Falklands War]] (1982).<ref name="Gibran">{{cite book|last1=Gibran|first1=Daniel K.|title=The Falklands War : Britain versus the past in the South Atlantic|date=1998|publisher=McFarland|location=Jefferson, N.C.|isbn=978-0786404063|page=161}}</ref>

Since [[Cold War (1985–91)|the end of the Cold War]], an increasingly international role for the armed forces has been pursued, with re-structuring to deliver a greater focus on [[expeditionary warfare]] and [[power projection]].<ref name="Adrian"/> This entailed the armed forces often constituting a major component in [[peacekeeping]] and humanitarian missions under the auspices of the United Nations, NATO, and other multinational operations,<ref>Frantzen (2005), ''Nato And Peace Support Operations, 1991–1999: Policies And Doctrines'', p104</ref> including: peacekeeping responsibilities in the [[Balkans]] and [[Cyprus]], the 2000 [[Operation Palliser|intervention in Sierra Leone]] and participation in the UN-mandated [[Libyan no-fly zone|no-fly zone over Libya]] (2011). Post-[[September 11 attacks|9/11]], the armed forces became heavily committed to the [[war on terror]] (2001–present), with lengthy campaigns in [[War in Afghanistan (2001–2021)|Afghanistan]] (2001–2021) and [[Iraq War|Iraq]] (2003–2009), and more recently as part of the [[Military intervention against ISIL]] (2014–present). Britain's military intervention against [[Islamic State of Iraq and the Levant|Islamic State]] was expanded following a parliamentary vote to launch a bombing campaign over [[Syria]]; an extension of the bombing campaign requested by the Iraqi government against the same group. In addition to the aerial campaign, the British Army has trained and supplied allies on the ground and the [[Special Air Service]], the [[Special Boat Service]], and the [[Special Reconnaissance Regiment]] (British special forces) has carried out various missions on the ground in both Syria and Iraq.

The armed forces have also been called upon to assist with national emergencies through the provisions of the [[military aid to the civil authorities]] (MACA) mechanism. This has seen the armed forces assist government departments and civil authorities responding to flooding, food shortages, wildfires, terrorist attacks and the [[COVID-19 pandemic in the United Kingdom|COVID-19 pandemic]];<ref>{{cite web |title=2015 to 2020 government policy: Military Aid to the Civil Authorities for activities in the UK |url=https://www.gov.uk/government/publications/2015-to-2020-government-policy-military-aid-to-the-civil-authorities-for-activities-in-the-uk/2015-to-2020-government-policy-military-aid-to-the-civil-authorities-for-activities-in-the-uk |website=GOV.UK |access-date=12 August 2021 |date=4 August 2016}}</ref> the armed forces' support to the latter falls under [[Operation Rescript]], described as the UK's "biggest ever homeland military operation in peacetime" by the Ministry of Defence.<ref name="peacetime">{{cite news |title=COVID Response Becomes Military's 'Biggest Homeland Operation In Peacetime' |url=https://www.forces.net/news/covid-response-militarys-biggest-homeland-operation-peacetime |access-date=11 January 2021 |work=[[BFBS]] |date=4 January 2021}}</ref>

Figures released by the Ministry of Defence on 31 March 2016 show that 7,185 British Armed Forces personnel have lost their lives in [[Military awards and decorations of the United Kingdom|medal earning]] theatres since the end of the Second World War.<ref name="Deaths">[https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/512070/20160331_UK_Armed_Forces_Operational_deaths_post_World_War_II.O.pdf UK Armed Forces Deaths: Operational deaths post World War II 3 September 1945 to 17 February 2016] {{Webarchive|url=https://web.archive.org/web/20160911093201/https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/512070/20160331_UK_Armed_Forces_Operational_deaths_post_World_War_II.O.pdf |date=11 September 2016 }}, Ministry of Defence, gov.uk, Published 31 March 2016</ref>

In 2025, under Prime Minister Keir Starmer, the UK published a new [[Strategic Defence Review (2025)|Strategic Defence Review]] (SDR) calling for a shift to "warfighting readiness". Major investments were announced, including the expansion of the [[SSN-AUKUS]] attack submarine program to up to 12 boats, acquisition of long-range weapons and advanced air-defence systems, and a possible entry into NATO's nuclear-sharing scheme via the F-35A platform.<ref>{{Cite news |title=Britain’s ambitious plan to rearm looks underfunded |url=https://www.economist.com/britain/2025/06/02/britains-ambitious-plan-to-rearm-looks-underfunded |access-date=2025-06-08 |work=The Economist |issn=0013-0613}}</ref>

==Today==
===Command===
[[File:ElizabethIItroopingcolour crop.jpg|thumb|right|alt=Elizabeth in red uniform on a black horse|Then Commander-in-Chief Queen Elizabeth II riding [[Burmese (horse)|Burmese]] at the 1986 [[Trooping the Colour]] ceremony]]
{{See also|UK parliamentary approval for military action}}
[[File:Ministry of Defence Main Building MOD 45150121.jpg|thumb|The [[Ministry of Defence (United Kingdom)|Ministry of Defence]] building at [[Whitehall]], [[City of Westminster|Westminster]], [[London]]]]
[[King Charles III]], [[sovereign of the United Kingdom]], is the [[Head of the British Armed Forces|Head of the Armed Forces]],<ref name="Forces Queen and Armed Forces"/><ref name="army.mod.uk"/> with officers and personnel swearing [[allegiance]] to him. Long-standing constitutional convention, however, has ''de facto'' vested military authority and associated [[Royal prerogative in the United Kingdom|royal prerogative powers]] in the [[Prime Minister of the United Kingdom|prime minister]] and the [[Secretary of State for Defence|secretary of state for defence]], with the former (acting with the support of the [[Cabinet of the United Kingdom|Cabinet]]) making the key decisions on the use of the armed forces. As the prime minister is not the formal head of the armed forces, the chief of the defence staff could refuse a direction by them to use the [[Nuclear weapons of the United Kingdom|UK's nuclear arsenal]].<ref>{{cite news|url=http://news.bbc.co.uk/1/hi/uk/7758314.stm|title=Whose hand is on the button?|access-date=14 March 2009|date=2 December 2008|publisher=BBC|archive-url=https://web.archive.org/web/20090221035555/http://news.bbc.co.uk/1/hi/uk/7758314.stm|archive-date=21 February 2009|url-status=live}}</ref>

The [[Ministry of Defence (United Kingdom)|Ministry of Defence]]{{efn|The current structure of defence management in Britain was set in place in 1964 when the modern day Ministry of Defence (MoD) was created (an earlier form had existed since 1940). The MoD assumed the roles of the [[British Admiralty|Admiralty]], the [[War Office]] and the [[Air Ministry]] }} is the government department charged with formulating and executing defence policy. It currently employs 56,860 civilian staff members as of 1 October 2015.<ref>[https://www.gov.uk/government/statistics/mod-civilian-personnel-quarterly-report-2015 MOD civilian personnel quarterly report: 2015] {{Webarchive|url=https://web.archive.org/web/20160311014359/https://www.gov.uk/government/statistics/mod-civilian-personnel-quarterly-report-2015 |date=11 March 2016 }}, gov.uk, 1 October 2015</ref> The department is administered by the secretary of state for defence who is assisted by the [[Minister of State for the Armed Forces]], [[Minister of State for Defence Procurement (UK)|Minister for Defence Procurement]], and Minister for Veterans' Affairs. Responsibility for the management of the forces is delegated to a number of committees: the [[Defence Council of the United Kingdom|Defence Council]], [[Chiefs of Staff Committee]], Defence Management Board and three single-service boards. The Defence Council, composed of senior representatives of the services and the Ministry of Defence, provides the "formal legal basis for the conduct of defence". The three constituent single-service committees ([[Admiralty Board]], [[Army Board]] and [[Air Force Board]]) are chaired by the secretary of state for defence.

The [[Chief of the Defence Staff (United Kingdom)|chief of the defence staff]] (CDS) is the senior-most officer of the armed forces and is an appointment that can be held by an [[admiral]], [[air chief marshal]] or [[general]]. Before the practice was discontinued in the 1990s, those who were appointed to the position of CDS had been elevated to the [[Five-star rank|most senior rank]] in their respective service.<ref>Hansard (1998), [https://publications.parliament.uk/pa/cm199798/cmhansrd/vo980512/text/80512w06.htm House of Commons Written Answers] {{Webarchive|url=https://web.archive.org/web/20170917213955/https://publications.parliament.uk/pa/cm199798/cmhansrd/vo980512/text/80512w06.htm |date=17 September 2017 }}, publications.parliament.uk</ref> The CDS, along with the permanent under secretary, are the principal military advisers to the secretary of state. All three services have their own respective professional chiefs; the [[First Sea Lord]] for the [[Royal Navy]], the [[Chief of the General Staff (United Kingdom)|chief of the general staff]] for the [[British Army|Army]] and the [[Chief of the Air Staff (United Kingdom)|chief of the air staff]] for the [[Royal Air Force]].

===Personnel===
[[File:Soldiers Trooping the Colour, 16th June 2007.jpg|thumb|[[Welsh Guards]] [[Trooping the Colour]]]]
As of 1 July 2025 the British Armed Forces are a professional force with a total strength of 180,779 personnel, consisting of 136,117 UK Regulars and 4,127 [[Brigade of Gurkhas|Gurkhas]], 31,967 [[Volunteer Reserves (United Kingdom)|Volunteer Reserve]]s and 8,568 "Other Personnel".{{efn|Other Personnel includes personnel of the [[Military Provost Guard Service]], [[Regular Reserve (United Kingdom)|Regular Reserves]] called up for duty and the [[Sponsored Reserves]].<ref name="quarterly personnel report"/>}}<ref name="quarterly personnel report">[https://www.gov.uk/government/statistics/quarterly-service-personnel-statistics-2023/quarterly-service-personnel-statistics-1-july-2023#uk-service-personnel]. UK Armed Forces: Quarterly Service Personnel Statistics. 1 July 2023. MoD. Published 17 September 2023. Retrieved 23 September 2023.</ref> As a percentage breakdown of UK Service Personnel, 77.1% are UK Regulars and Gurkhas, 18.8% are Volunteer Reserves and 4.1% are composed of Other Personnel.<ref name="quarterly personnel report"/> In addition, all ex-Regular personnel retain a "statutory liability for service" and are liable to be recalled (under Section 52 of the Reserve Forces Act (RFA) 1996) for duty during wartime, which is known as the [[Regular Reserve (United Kingdom)|Regular Reserve]]. MoD publications since April 2013 no longer report the entire strength of the Regular Reserve, instead they only give a figure for Regular Reserves who serve under a fixed-term reserve contract. These contracts are similar in nature to those of the Volunteer Reserve.<ref name="Regular Reserve">[https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/314795/uk_reserve_force_cadets_2014.pdf gov.uk MoD – reserves and cadet strengths] {{Webarchive|url=https://web.archive.org/web/20160308182849/https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/314795/uk_reserve_force_cadets_2014.pdf |date=8 March 2016 }}, table 4 page 13. See note 2. April 2014.</ref>

The distribution of personnel between the services and categories of service on 1 January 2025 was as follows:<ref name="quarterly personnel report" />

{| class="wikitable"
|-
! Service !! Regular !! Volunteer<br />Reserve !! Other<br />personnel !! Total
|-
| Navy || align="right"| 31,906 || align="right"| 3,217 || align="right"| 2,478 || align="right"| '''37,601'''
|-
| Army and Gurkhas|| align="right"| 77,974 || align="right"| 25,742, || align="right"| 4,697 || align="right"| '''108,413'''
|-
| Air Force || align="right"| 30,364 || align="right"| 3,008 || align="right"| 1,393 || align="right"| '''34,765'''
|-
| '''Total''' || align="right"| '''140,244''' || align="right"| '''31,967''' || align="right"| '''8,568''' || align="right"| '''180,779'''
|}
On 1 April 2024, most personnel in the UK Regular Forces were stationed in the United Kingdom (around 96%).<ref name=":3">{{Cite web |date=13 Aug 2024 |title=UK defence personnel statistics - House of Commons Library |url=https://commonslibrary.parliament.uk/research-briefings/cbp-7930/ |last1=Kirk-Wade |first1=Esme }}</ref>

Of the 5,700 personnel stationed overseas, around two thirds were in Europe (66%), while 14% were stationed in North America, 6% in North Africa and the Middle East, 6% in Asia and 5% in Sub-Saharan Africa.<ref name=":3" /> 1,230 personnel were distributed across several regions in Germany, primarily [[North Rhine-Westphalia]] as part of [[British Army Germany]]. However, up to 750 of these were Locally Engaged Civilians.<ref>{{Cite web |last=Allison |first=George |date=2024-10-26 |title=British troops in Germany draws down to 1,200 from 30,000 |url=https://ukdefencejournal.org.uk/british-troops-in-germany-draws-down-to-1200-from-30000/ |access-date=2024-11-22 |language=en-GB}}</ref>

===Defence expenditure===
{{See also|List of countries in Europe by military expenditures}}[[File:Top ten military expenditures in US$ Bn. in 2014, according to the International Institute for Strategic Studies.PNG|thumb|Top ten military expenditures in billion US$ in 2014]]
According to the [[Stockholm International Peace Research Institute]], the United Kingdom is in sixth place in the world's military spending list in 2024.<ref name=":2">{{Cite web |date= |title=Trends in World Military expenditure 2024 |url=https://www.sipri.org/sites/default/files/2025-04/2504_fs_milex_2024.pdf#page=2 |access-date=2024-05-04 |website=sipri.org |format=PDF}}</ref> For comparison: Great Britain spends more in absolute terms than Saudi Arabia, Ukraine, France or Japan, but less than India, Germany, Russia, China or the United States.<ref name=":2" /> In September 2011, according to Professor Malcolm Chalmers of the [[Royal United Services Institute]], current "planned levels of defence spending should be enough for the United Kingdom to maintain its position as one of the world's top military powers, as well as being one of NATO-Europe's top military powers. Its edge – not least its qualitative edge – in relation to rising Asian powers seems set to erode, but will remain significant well into the 2020s, and possibly beyond."<ref>[https://rusi.org/system/files/RUSIBriefingPaperSept2011.pdf RUSI Briefing Paper] {{Webarchive|url=https://web.archive.org/web/20160816202255/https://rusi.org/system/files/RUSIBriefingPaperSept2011.pdf |date=16 August 2016 }}, Is the UK Defence Budget Crisis Really Over?. Malcolm Chalmers. Published September 2011, p. 18</ref> The [[Strategic Defence and Security Review 2015]] committed to spending 2% of GDP on defence and announced a £178&nbsp;billion investment over ten years in new equipment and capabilities.<ref>{{cite news|title=UK announces rapid strike forces, more warships in new defence plan|url=http://uk.reuters.com/article/uk-britain-defence-idUKKBN0TC0V120151123|access-date=23 November 2015|work=Reuters|date=23 November 2015|archive-url=https://web.archive.org/web/20151124125230/http://uk.reuters.com/article/2015/11/23/uk-britain-defence-idUKKBN0TC0V120151123|archive-date=24 November 2015|url-status=dead}}</ref><ref>{{cite web|title=PM pledges £178 billion investment in defence kit|url=https://www.gov.uk/government/news/pm-pledges-178-billion-investment-in-defence-kit|publisher=Ministry of Defence|access-date=23 November 2015|date=23 November 2015|archive-url=https://web.archive.org/web/20151123145305/https://www.gov.uk/government/news/pm-pledges-178-billion-investment-in-defence-kit|archive-date=23 November 2015|url-status=live}}</ref> On 8 March 2023 Prime Minister [[Rishi Sunak]] announced a further £5bn in defence spending with a long-term goal of an increased spending to 2.5% of GDP.<ref>{{Cite news |date=13 March 2023 |title=Rishi Sunak: China represents challenge to world order |language=en-GB |work=BBC News |url=https://www.bbc.com/news/uk-politics-64943445 |access-date=14 March 2023}}</ref>

===Nuclear weapons===
{{Main|Nuclear weapons of the United Kingdom}}
[[File:Trident II missile image.jpg|thumb|A [[UGM-133 Trident II|Trident II SLBM]] being launched from a {{sclass|Vanguard|submarine|2}}]]
The United Kingdom is one of five recognised nuclear weapon states under the [[Treaty on the Non-Proliferation of Nuclear Weapons|Non-Proliferation Treaty]] and maintains an independent [[Deterrence theory|nuclear deterrent]], currently consisting of four {{sclass|Vanguard|submarine|0}} [[ballistic missile submarine]]s, [[UGM-133 Trident II]] [[submarine-launched ballistic missile]]s, and 160 operational [[Thermonuclear weapon|thermonuclear warheads]]. This is known as [[Trident nuclear programme|Trident]] in both public and political discourse (with nomenclature taken after the UGM-133 Trident II ballistic missile). Trident is operated by the [[Royal Navy Submarine Service]], charged with delivering a 'Continuous At-Sea Deterrent' (CASD) capability, whereby one of the ''Vanguard''-class strategic submarines is always on patrol.<ref name="CASD">[http://www.royalnavy.mod.uk/news-and-latest-activity/operations/global/continuous-at-sea-deterrent Royal Navy – Continuous at sea deterrent] {{Webarchive|url=https://web.archive.org/web/20141209103234/http://www.royalnavy.mod.uk/news-and-latest-activity/operations/global/continuous-at-sea-deterrent |date=9 December 2014 }}, royalnavy.mod.uk, Accessed 6 December 2014</ref> According to the British Government, since the introduction of [[UK Polaris programme|Polaris]] (Trident's predecessor) in the 1960s, from April 1969 "the Royal Navy's ballistic missile boats have not missed a single day on patrol",<ref name="CASD"/> giving what the [[Defence Council of the United Kingdom|Defence Council]] described in 1980 as a deterrent "effectively invulnerable to pre-emptive attack".<ref name="Future Deterrent">{{cite web | url=http://www.margaretthatcher.org/document/6AC6FE79AE5E485DB3A2B579B6AE0654.pdf | title=The Future United Kingdom Strategic Deterrent Force | publisher=The Defence Council | date=July 1980 | access-date=17 May 2012}}</ref> As of 2015, it has been British Government policy for the ''Vanguard''-class strategic submarines to carry no more than 40 nuclear warheads, delivered by eight UGM-133 Trident II ballistic missiles.<ref>[https://publications.parliament.uk/pa/cm201415/cmhansrd/cm150120/wmstext/150120m0001.htm#15012039000004 House of Commons Hansard - Written Statements - Nuclear Deterrent] {{Webarchive|url=https://web.archive.org/web/20170917213853/https://publications.parliament.uk/pa/cm201415/cmhansrd/cm150120/wmstext/150120m0001.htm#15012039000004 |date=17 September 2017 }}, publications.parliament.uk, 20 January 2015</ref> In contrast with the other recognised nuclear weapon states, the United Kingdom operates only a submarine-based delivery system, having decommissioned its tactical [[WE.177]] free-fall bombs in 1998.

The [[House of Commons of the United Kingdom|House of Commons]] voted on 18 July 2016 in favour of replacing the ''Vanguard''-class submarines with a new generation of {{sclass|Dreadnought|submarine|1}}s.<ref>{{cite news |url=https://www.bbc.com/news/uk-politics-36830923 |date=19 July 2016 |newspaper=[[BBC News Online]] |title=MPS vote to renew Trident weapons system - BBC News |access-date=21 July 2018 |archive-url=https://web.archive.org/web/20160718213716/http://www.bbc.com/news/uk-politics-36830923 |archive-date=18 July 2016 |url-status=live}}</ref> The programme will also contribute to extending the life of the UGM-133 Trident II ballistic missiles and modernise the infrastructure associated with the CASD.<ref name="WhitePaper">{{cite web|url=http://www.mod.uk/NR/rdonlyres/AC00DD79-76D6-4FE3-91A1-6A56B03C092F/0/DefenceWhitePaper2006_Cm6994.pdf|title=The Future of the United Kingdom's Nuclear Deterrent|date=4 December 2006|publisher=[[Ministry of Defence (United Kingdom)|Ministry of Defence]]|access-date=5 December 2006|archive-url=https://web.archive.org/web/20061206004317/http://www.mod.uk/NR/rdonlyres/AC00DD79-76D6-4FE3-91A1-6A56B03C092F/0/DefenceWhitePaper2006_Cm6994.pdf|archive-date=6 December 2006|url-status=live}}</ref>

Former [[United Kingdom and weapons of mass destruction|weapons of mass destruction possessed by the United Kingdom]] include both biological and [[Chemical weapons and the United Kingdom|chemical weapons]]. These were renounced in 1956 and subsequently destroyed.

===Overseas military installations===
{{Main|Overseas military bases of the United Kingdom}}
[[File:United Kingdom overseas military installations and operations.png|thumb|British overseas military installations]]
{{Legend|#0000FF|Overseas military installations of the United Kingdom, and locally raised units of [[British Overseas Territories]].}}
{{Legend|#F0002B|Military interventions since 2000: [[British military intervention in the Sierra Leone Civil War|Palliser]] (Sierra Leone); [[Operation Herrick|Herrick]] (Afghanistan); [[Operation Enduring Freedom – Horn of Africa|Enduring Freedom]] (Horn of Africa); [[Operation Telic|Telic]] (Iraq); [[Operation Ellamy|Ellamy]] (Libya); and [[Operation Shader|Shader]] (Islamic State of Iraq and the Levant).}}

The British Armed Forces historically relied on four [[Imperial fortress]] colonies (Bermuda,<ref>{{cite book |last=Harris |first=Edward C. |author-link=Edward C. Harris |title=Bermuda Forts 1612–1957 |year=1997 |location=Bermuda |publisher=The Bermuda Maritime Museum Press |isbn=9780921560111}}</ref> Gibraltar, Halifax and its environs in Nova Scotia, and Malta),<ref>{{cite Hansard |jurisdiction=Parliament of the United Kingdom |title=SUPPLY—ARMY ESTIMATES |url=https://api.parliament.uk/historic-hansard/commons/1839/mar/22/supply-army-estimates |house=House of Commons |date=22 March 1839 |volume=46 |column_start=1141 |column_end=1142 |speaker=Sir Henry Hardinge |position=MP for Launceston}}</ref> where dockyards were established, naval squadrons based, soldiers garrisoned,<ref>{{cite magazine |last=Kennedy, R.N. |first=Captain W. R. |date=1 July 1885 |title=An Unknown Colony: Sport, Travel and Adventure in Newfoundland and the West Indies |url= |magazine=Blackwood's Edinburgh Magazine |location= |publisher=William Blackwood & Sons, Edinburgh, Scotland, and 37 Paternoster Row, London, England |access-date= |page=111}}</ref><ref>{{cite magazine |last=VERAX |first=(anonymous) |date=1 May 1889 |title=The Defense of Canada. (From Colburn's United Service Magazine) |url= |magazine=The United Service: A Quarterly Review of Military and Naval Affairs |location= |publisher=LR Hamersly & Co., 1510 Chestnut Street, Philadelphia, Pennsylvania, USA; subsequently LR Hamersly, 49 Wall Street, New York City, New York, USA; BF Stevens & Brown, 4 Trafalgar Square, London, England |access-date= |page=552}}</ref><ref>{{cite book |last1=Dawson |first1=George M. |last2=Sutherland |first2=Alexander |author-link= |date=1898 |title=MacMillan's Geographical Series: Elementary Geography of the British Colonies |url= |location=London |publisher=MacMillan and Co., Limited, London, England, UK; The MacMillan Company, New York City, New York, USA |page=184 |isbn= }}</ref> and naval and military stores stockpiled.<ref>{{cite book |last=Willock [[United States Marine Corps|USMC]] |first=Lieutenant-Colonel Roger |title=Bulwark Of Empire: Bermuda's Fortified Naval Base 1860–1920 |year=1988 |location=Bermuda |publisher=The Bermuda Maritime Museum Press |isbn=9780921560005}}</ref><ref>{{cite book |last=Gordon |first=Donald Craigie |author-link= |date=1965 |title=The Dominion Partnership in Imperial Defense, 1870-1914 |url= |location=Baltimore, Maryland, USA |publisher=Johns Hopkins Press |page=14 |isbn= }}</ref><ref>{{cite book |last=MacFarlane |first=Thomas |author-link= |date=1891 |title=Within the Empire; An Essay on Imperial Federation |url= |location=Ottawa |publisher=James Hope & Co., Ottawa, Ontario, Canada |page=29 |isbn= }}</ref> These acted as lynchpins in maintaining British naval supremacy on the Atlantic and its connected seas.<ref>{{cite web|title=Attack on Baltimore launched from Bermuda in 'War of 1812'|publisher=Atlas Communications|url=http://www.atlascom.us/defender.htm|year=2005|access-date=4 May 2023|archive-date=3 October 2018|archive-url=https://web.archive.org/web/20181003233516/http://www.atlascom.us/defender.htm|url-status=dead}}</ref><ref>''The Andrew and The Onions: The Story of The Royal Navy in Bermuda, 1795–1975'', by Lieutenant-Commander B. Ian D. Stranack. Bermuda Maritime Museum Press</ref><ref>{{Cite web |url=http://bermuda-online.org/britarmy.htm |title=Bermuda Online: British Army in Bermuda from 1701 to 1977; 1881 to 1883 |access-date=22 June 2020 |archive-url=https://web.archive.org/web/20140821111911/http://www.bermuda-online.org/britarmy.htm |archive-date=21 August 2014 |url-status=dead }}</ref><ref>{{cite news |last=Harris |first=Dr. Edward Cecil |date=21 January 2012 |title=Bermuda's role in the Sack of Washington |url=https://www.royalgazette.com/archive/lifestyle/article/20120121/bermudas-role-in-the-sack-of-washington/ |work=The Royal Gazette |location=City of Hamilton, Pembroke, Bermuda |access-date=8 August 2021}}</ref><ref>{{cite magazine |last=Grove |first=Tim |date=22 January 2021 |title=Fighting The Power |url=https://chesapeakebaymagazine.com/fighting-the-power/ |magazine=Chesapeake Bay Magazine |location=Annapolis |publisher=Chesapeake Bay Media, LLC |access-date=8 August 2021}}</ref> As, until the end of the First World War, it was presumed the only navies that might prove a threat were all of countries on, or off, the Atlantic, no Imperial fortress was established in the Pacific or Indian Oceans, to which power would be extended from Bermuda and Malta following the completion of the Panama and Suez canals. Local-service military reserve units were raised in some of the Imperial fortresses (notably Bermuda and Malta), which could be embodied for full time service in war time to reinforce the regular garrisons, and these were funded by the War Office as part of the British Army. After the First World War, the growing belligerence and naval power of the Japanese Empire led to the construction of the Singapore Naval Base. The regular British Armed Forces otherwise were distributed around the world, were required to guard against invasion or rebellion, reinforced in some colonies by locally raised reserve forces. In colonies where there was no strategic requirement, regular forces were rarely stationed, with local governments encouraged to maintain and fund military reserve units as contributions to their own defence (although these units were ultimately under the control of the national, i.e. British, Government via the colonial Governors as defence is not a competency that has been delegated to local governments). Under the North Atlantic Treaty Organisation alliance, and with the steady reduction of both the British Empire and the British Armed Forces over the decades that followed the Second World War, the significance of the three remaining Imperial fortresses (military control of Halifax having passed to the new Dominion government following the 1867 [[Confederation of Canada]], and naval control transferred in 1905 to what was to become the [[Royal Canadian Navy]]) rapidly faded. The Bermuda-based [[North America and West Indies Station]] was abolished in 1956, and the last regular army units removed from the Bermuda Command in 1957 (leaving only two part-time reserve units), with the naval dockyard in Bermuda reduced to a base,<ref>{{cite book |last=Stranack, Royal Navy |first=Lieutenant-Commander B. Ian D |date=1977 |title=The Andrew and The Onions: The Story of The Royal Navy in Bermuda, 1795–1975 |url= |location=Bermuda |publisher=Island Press Ltd <!--., Bermuda, 1977 (1st Edition); Bermuda Maritime Museum Press, Royal Naval Dockyard Bermuda, Ireland Island, Sandys, Bermuda, 1990 (2nd Edition)--> |page= |isbn=9780921560036}}</ref> without repair or refit capabilities, in 1951 and finally closed in 1995, following the Cold War (United States and Canadian bases in Bermuda closed in the same period), leaving only the [[Royal Bermuda Regiment]] and the [[Bermuda Sea Cadet Corps]] there today.<ref>{{cite web |url=https://whc.unesco.org/en/list/983/multiple=1&unique_number=1147 |title=World Heritage List: Historic Town of St George and Related Fortifications, Bermuda |author=<!--Not stated--> |date=<!--Not stated-->  |publisher=UNESCO |access-date=28 July 2021 }}</ref> Malta became independent in 1964, and the last British armed forces personnel were removed from the former colony in 1979. Gibraltar continues to be used by the regular British Armed Forces, though the naval and military establishment in the colony (now termed a ''British Overseas Territory'') has been reduced to several Royal Naval patrol craft, the locally raised [[Royal Gibraltar Regiment]], and a [[Royal Air Force Station]] without aircraft based on it.

The British Armed Forces today maintain a number of overseas garrisons and military facilities which enable the country to conduct operations worldwide. The majority of Britain's permanent military installations are located on [[British Overseas Territories]] (BOTs) or [[British Empire|former colonies]] which retain close diplomatic ties with the United Kingdom, and located in areas of strategic importance.<ref name=europarl/> The most significant of these are the "Permanent Joint Operating Bases" (PJOBs), located on the four overseas territories of Cyprus ([[British Forces Cyprus]]), Gibraltar ([[British Forces Gibraltar]]), the Falkland Islands ([[Military of the Falkland Islands|British Forces South Atlantic Islands]]) and Diego Garcia ([[British Forces British Indian Ocean Territories]]).<ref>{{cite web |url=https://www.gov.uk/government/publications/permanent-joint-operating-bases-pjobs/permanent-joint-operating-bases-pjobs |title=Permanent Joint Operating Bases (PJOBs) |archive-url=https://web.archive.org/web/20160322052411/https://www.gov.uk/government/publications/permanent-joint-operating-bases-pjobs/permanent-joint-operating-bases-pjobs |archive-date=22 March 2016 |publisher=Government of the United Kingdom |date=12 December 2012}}</ref> While not a PJOB, Ascension Island (another BOT) is home to the airbase [[RAF Ascension Island]], notable for use as a staging post during the 1982 [[Falklands War]], the territory is also the site of a joint UK-US [[signals intelligence]] facility.<ref name=europarl>{{cite journal|title=The Status and Location of the Military Installations of the Member States of the European Union|journal=Policy Department External Policies|date=February 2009|pages=13–14|url=http://www.europarl.europa.eu/meetdocs/2004_2009/documents/dv/sede300309studype407004_/SEDE300309StudyPE407004_en.pdf|access-date=21 October 2014|archive-url=https://web.archive.org/web/20150924052522/http://www.europarl.europa.eu/meetdocs/2004_2009/documents/dv/sede300309studype407004_/SEDE300309StudyPE407004_en.pdf|archive-date=24 September 2015|url-status=live}}</ref>

Qatar is home to [[RAF Al Udeid]], a Royal Air Force outpost at [[Al Udeid Air Base]] which serves as the operational headquarters for [[No. 83 Expeditionary Air Group (United Kingdom)|No. 83 Expeditionary Air Group]] and its operations across the Middle East.<ref>{{cite news |title=UK and Qatar sign pact to combat jihadis and cyber warfare |url=https://www.ft.com/cms/s/0/4d16d268-629b-11e4-9838-00144feabdc0.html |access-date=3 November 2015 |agency=Financial Times |date=2 November 2014 |url-status=dead |archive-url=https://web.archive.org/web/20150108184343/http://www.ft.com/cms/s/0/4d16d268-629b-11e4-9838-00144feabdc0.html |archive-date=8 January 2015}}</ref> A large Royal Navy [[HMS Jufair|Naval Support Facility]] (NSF) is located in Bahrain, established in 2016 it marks the British return East of Suez.<ref>{{cite news|title=Royal Navy's new Bahrain base seriously enhances Britain's ability to defend the Gulf|url=https://www.telegraph.co.uk/news/2016/11/10/todays-opening-of-the-royal-navys-new-bahrain-base-seriously-enh/|access-date=17 November 2016|newspaper=The Telegraph|date=10 November 2016|archive-url=https://web.archive.org/web/20161117211730/http://www.telegraph.co.uk/news/2016/11/10/todays-opening-of-the-royal-navys-new-bahrain-base-seriously-enh/|archive-date=17 November 2016|url-status=live}}</ref> In support of the [[Five Power Defence Arrangements]] (FPDA), the United Kingdom retains a naval repair and logistics support facility at [[Sembawang|Sembawang wharf]], Singapore.<ref name=europarl/><ref name="NP1022">{{cite book|title=Navy News (Magazine)|date=June 2011|publisher=Royal Navy|location=United Kingdom|page=11 Eastern Outpost|url=https://issuu.com/magarchive/docs/201106|access-date=22 June 2016|archive-date=25 March 2020|archive-url=https://web.archive.org/web/20200325173731/https://issuu.com/magarchive/docs/201106|url-status=dead}} ("''The White Ensign is still flying above the operations of Naval Party 1022 (NP1022), based at Sembawang Wharves in Singapore.''")</ref> Other overseas military installations include; [[British Forces Brunei]],<ref name="Brunei">{{cite web|title=The British Army in Brunei|url=http://www.army.mod.uk/operations-deployments/22792.aspx|website=www.army.mod.uk/|publisher=Ministry of Defence|access-date=20 June 2016|archive-url=https://web.archive.org/web/20160609090139/http://www.army.mod.uk/operations-deployments/22792.aspx|archive-date=9 June 2016|url-status=live}}</ref> [[British Army Germany]],<ref name="Germany">{{cite web|title=The British Army in Germany|url=http://www.army.mod.uk/operations-deployments/22729.aspx|website=www.army.mod.uk/|publisher=Ministry of Defence|access-date=20 June 2016|archive-url=https://web.archive.org/web/20160605063435/http://www.army.mod.uk/operations-deployments/22729.aspx|archive-date=5 June 2016|url-status=live}}</ref> the [[British Army Training Unit Kenya]],<ref name="Africa">{{cite web|title=The British Army in Africa|url=http://www.army.mod.uk/operations-deployments/22724.aspx|website=www.army.mod.uk/|publisher=Ministry of Defence|access-date=20 June 2016|archive-url=https://web.archive.org/web/20160630055845/http://www.army.mod.uk/operations-deployments/22724.aspx|archive-date=30 June 2016|url-status=live}}</ref> [[British Army Training Unit Suffield]] in Canada,<ref name="Canada">{{cite web|title=The British Army in Canada|url=http://www.army.mod.uk/operations-deployments/22727.aspx|website=www.army.mod.uk/|publisher=Ministry of Defence|access-date=20 June 2016|archive-url=https://web.archive.org/web/20160605063606/http://www.army.mod.uk/operations-deployments/22727.aspx|archive-date=5 June 2016|url-status=live}}</ref> [[British Army Training and Support Unit Belize]], and [[British Gurkhas Nepal]].<ref name="Nepal">{{cite web|title=British Gurkhas Nepal|url=http://www.army.mod.uk/gurkhas/27825.aspx|website=www.army.mod.uk/|publisher=Ministry of Defence|access-date=23 June 2016|archive-url=https://web.archive.org/web/20160704143134/http://www.army.mod.uk/gurkhas/27825.aspx|archive-date=4 July 2016|url-status=live}}</ref>

Some British Overseas Territories also maintain locally raised units and regiments; [[The Royal Bermuda Regiment]], the [[Falkland Islands Defence Force]], the [[Royal Gibraltar Regiment]], the [[Royal Montserrat Defence Force]], the [[Cayman Islands Regiment]], and the [[Turks and Caicos Regiment]]. Though their primary mission is "home defence", individuals have volunteered for operational duties. The Royal Bermuda Regiment  is an amalgam of the [[Bermuda Militia Artillery]] (which had been part of the [[Royal Regiment of Artillery]]) and the [[Bermuda Volunteer Rifle Corps]],<ref>{{cite book |last=Ingham-Hind |first=Jennifer M. |title=Defence, Not Defiance: A History Of The Bermuda Volunteer Rifle Corps |year=1992 |location=Bermuda |publisher=The Island Press |isbn=0969651716}}</ref> raised in the 1890s as Imperial forces funded by the War Office as part of the British Army,<ref>{{cite book |last=Maurice-Jones|first=Colonel |author-link= |date=1959 |title=History of The Coast Artillery in the British Army |url= |location=UK |publisher=Royal Artillery Institution |page= |isbn=1781491151}}</ref> and both antecedent units sent contingents to the Western Front during the First World War. They also sent contingents that served in North-Western Europe, and Italy and North Africa during the Second World War. The Royal Gibraltar Regiment mobilised section-sized units for attachment to British regiments deployed during the [[Iraq War]].<ref>{{cite web |url=http://www.1rg.gi/theregiment/regular/operations.qxp |title=The Royal Gibraltar Regiment |archive-url=https://web.archive.org/web/20070928004525/http://www.1rg.gi/theregiment/regular/operations.qxp |archive-date=28 September 2007 |website=1rg.gi}}</ref><ref>{{cite web |url=http://www.panorama.gi/archive/050110/updates.htm#More%20soldiers |url-status=dead |title=More soldiers from Royal Gibraltar Regiment in overseas duties in regiment's history |work=Gibraltar Panorama |archive-url=https://web.archive.org/web/20070927004314/http://www.panorama.gi/archive/050110/updates.htm#More%20soldiers |archive-date=27 September 2007}}</ref> The [[Isle of Man]], a [[Crown dependency]] hosts a multi-capability recruiting and training unit of the [[Army Reserve (United Kingdom)|British Army Reserve]].<ref name="Isle of Man Army Reserve">{{Cite news|title=British Army opens first reserve unit opens on Isle of Man since 1968|url=https://www.bbc.com/news/world-europe-isle-of-man-34401508|journal=BBC News|access-date=24 October 2016|date=October 2015|archive-url=https://web.archive.org/web/20161025115619/http://www.bbc.com/news/world-europe-isle-of-man-34401508|archive-date=25 October 2016|url-status=live}}</ref>

Since 1969 Britain has had a military satellite communications system, [[Skynet (satellite)|Skynet]], initially in large part to support [[East of Suez]] bases and deployments. Since 2015 Skynet has offered near global coverage.<ref name=defenceconnect-20160516>{{cite news |url=https://www.defenceconnect.com.au/intel-cyber/4-skynet-in-australia |title=Skynet in Australia |website=Defence Connect |date=16 May 2016 |access-date=20 February 2021}}</ref>

===Expeditionary forces===
The British Armed Forces place significant importance in the ability to conduct [[expeditionary warfare]].<ref name="Adrian">{{cite book|last1=Hyde-Price|first1=Adrian (Professor)|title=European Security in the Twenty-First Century: The Challenge of Multipolarity|date=9 January 2007|publisher=Routledge|isbn=978-1134164400|page=Chapter - Britain, France and the multipolar challenge|url=https://books.google.com/books?id=kqE4ssDSrOAC&q=European+Security+in+the+Twenty-First+Century:+The+Challenge+of+Multipolarity|access-date=26 June 2016}} Professor of International Politics, Adrian Hyde-Price, highlights that in the post-[[Cold War]] era both Britain and France have re-focused their attention ''"towards [[expeditionary warfare]] and [[power projection]]. Power projection has always been an element of British and French military thinking given their residual overseas interests, but it has now moved centre stage."''</ref> While the armed forces are expeditionary in nature, it maintains a core of "high readiness" forces trained and equipped to deploy at very short notice, these include; the [[Joint Expeditionary Force (Maritime)]] (Royal Navy), [[United Kingdom Commando Force|UK Commando Force]] (Royal Marines), and [[16 Air Assault Brigade]] (British Army). Frequently, these forces will act as part of a larger tri-service effort, under the direction of [[Permanent Joint Headquarters]], or along with like-minded allies under the [[Joint Expeditionary Force]]. Similarly, under the auspices of [[NATO]], such expeditionary forces are designed to meet Britain's obligations to the [[Allied Rapid Reaction Corps]] and other NATO operations.

In 2010, the governments of the United Kingdom and [[France]] signed the [[The Lancaster House Treaties (2010)|Lancaster House Treaties]] which committed both governments to the creation of a Franco-British [[Combined Joint Expeditionary Force]].<ref>{{cite news|url=https://www.theguardian.com/politics/2010/nov/02/britain-france-landmark-50-year-defence-deal|location=London|work=The Guardian|first=Patrick|last=Wintour|title=Britain and France sign landmark 50-year defence deal|date=2 November 2010|access-date=14 December 2016|archive-url=https://web.archive.org/web/20170202112114/https://www.theguardian.com/politics/2010/nov/02/britain-france-landmark-50-year-defence-deal|archive-date=2 February 2017|url-status=live}}</ref> It is envisaged as a deployable joint force, for use in a wide range of crisis scenarios, up to and including high intensity combat operations. As a joint force it involves all three armed Services: a land component composed of formations at national brigade level, maritime and air components with their associated Headquarters, together with logistics and support functions.<ref>{{cite web |url=http://www.number10.gov.uk/news/statements-and-articles/2010/11/uk%E2%80%93france-summit-2010-declaration-on-defence-and-security-co-operation-56519 |title=Tuesday 2 November 2010 UK–France Summit 2010 Declaration on Defence and Security Co-operation |publisher=Number10.gov.uk |access-date=26 June 2016 |archive-url=https://web.archive.org/web/20110705102530/http://www.number10.gov.uk/news/statements-and-articles/2010/11/uk%e2%80%93france-summit-2010-declaration-on-defence-and-security-co-operation-56519 |archive-date=5 July 2011 |url-status=live}}</ref>

==Branches==
===Royal Navy===
{{Main|Royal Navy}}
[[File:HMS Queen Elizabeth (R08) underway during trials with HMS Sutherland (F81) and HMS Iron Duke (F234) on 28 June 2017 (45162784).jpg|thumb|{{HMS|Queen Elizabeth|R08|6}}, a [[Queen Elizabeth-class aircraft carrier|''Queen Elizabeth''-class]] [[supercarrier]] on sea trials in June 2017]]

The Royal Navy is a technologically sophisticated naval force,<ref>{{cite web |url=http://www.royalnavy.mod.uk/ |title=Royal Navy |publisher=royalnavy.mod.uk |access-date=1 October 2014 |archive-url=https://web.archive.org/web/20140930153653/http://www.royalnavy.mod.uk/ |archive-date=30 September 2014 |url-status=live}}</ref> and as of September 2025 consists of [[List of active Royal Navy ships|64 commissioned ships]] with an additional 10 support vessels of various types operated by the [[Royal Fleet Auxiliary]]. Command of deployable assets is exercised by the [[Fleet Commander]] of the [[His Majesty's Naval Service|Naval Service]].<ref>[http://www.armedforces.co.uk/navy/listings/l0006.html Fleet Command and Organisation] {{Webarchive|url=https://web.archive.org/web/20070202121128/http://www.armedforces.co.uk/navy/listings/l0006.html |date=2 February 2007 }}, armedforces.co.uk</ref> Personnel matters are the responsibility of the [[Second Sea Lord]]/Commander-in-Chief Naval Home Command, an appointment usually held by a vice-admiral.<ref>[https://www.royalnavy.mod.uk/static/content/209.html] {{webarchive|url=https://web.archive.org/web/20050514111544/https://www.royalnavy.mod.uk/static/content/209.html|date=14 May 2005}}</ref>

The Surface Fleet consists of [[aircraft carrier]]s, [[destroyer]]s, [[frigate]]s, [[Patrol boat|patrol vessels]], [[Minesweeper|mine-countermeasure vessels]], and other miscellaneous vessels. The Surface Fleet has been structured around a single fleet since the abolition of the [[Eastern Fleet|Eastern]] and [[Western Fleet (United Kingdom)|Western]] fleets in 1971.<ref>Hampshire (1975), ''The Royal Navy Since 1945: its transition to the nuclear age'', p248</ref> The recently built [[Type 45 destroyer]]s are stealthy and technologically advanced air-defence destroyers. The Royal Navy has commissioned two {{sclass|Queen Elizabeth|aircraft carrier|2}}<nowiki/>s, embarking an air-group including the advanced fifth-generation multi-role fighter, the [[Lockheed Martin F-35 Lightning II|F-35B Lightning]].<ref>{{cite news|url=http://news.bbc.co.uk/2/hi/uk_news/scotland/6914788.stm|work=BBC News|title=MoD confirms £3.8bn carrier order|date=25 July 2007|access-date=27 April 2010|archive-url=https://web.archive.org/web/20090911215317/http://news.bbc.co.uk/2/hi/uk_news/scotland/6914788.stm|archive-date=11 September 2009|url-status=live}}</ref>

A submarine service has existed within the Royal Navy for more than 100 years. The [[Royal Navy Submarine Service|Submarine Service]]'s four {{sclass|Vanguard|submarine|0}} nuclear-powered submarines carry [[UGM-133 Trident II|Trident II ballistic missiles]], forming the [[Nuclear weapons of the United Kingdom|United Kingdom's nuclear deterrent]]. Seven {{sclass|Astute|submarine|0}} nuclear-powered fleet (attack) submarines have been ordered, with six completed and one under construction. The ''Astute'' class are the most advanced and largest fleet submarines ever built for the Royal Navy and will maintain Britain's nuclear-powered submarine fleet capabilities for decades to come.

====Royal Marines====
{{Main|Royal Marines}}
The Royal Marines are the Royal Navy's amphibious troops. Consisting of a single manoeuvre brigade (UK Commando Force) and various independent units, the Royal Marines specialise in [[amphibious warfare|amphibious]], [[arctic warfare|arctic]], and [[mountain warfare]].<ref>BBC News (19 March 2002), "[http://news.bbc.co.uk/1/hi/uk/1593996.stm UK's mountain warfare elite]". {{Webarchive|url=https://web.archive.org/web/20070221144849/http://news.bbc.co.uk/1/hi/uk/1593996.stm |date=21 February 2007 }}.</ref> Contained within UK Commando Force are three attached army units; 383 Commando Petroleum Troop RLC, [[29th Commando Regiment Royal Artillery]], a field artillery regiment based in Plymouth, and [[24 Commando Regiment Royal Engineers]].<ref>{{cite web |url=http://www.army.mod.uk/infantry/regts/the_rifles/rifles_hq/commando_role.htm |title=The Commando Role for 1 RIFLER |website=The British Army |date=30 January 2007 |url-status=dead |archive-url=https://web.archive.org/web/20071018102124/http://army.mod.uk/infantry/regts/the_rifles/rifles_hq/commando_role.htm |archive-date= 18 October 2007 }}</ref> The [[Commando Logistic Regiment]] consists of personnel from the Army, Royal Marines, and Royal Navy.<ref>{{cite web |url-status=dead |url=https://www.royalnavy.mod.uk/static/content/2540.html |title=Commando Logistic Regiment: About the Regiment |website= Royal Navy |archive-url=https://web.archive.org/web/20050514133822/https://www.royalnavy.mod.uk/static/content/2540.html |archive-date=14 May 2005 }}</ref>

===British Army===
{{Main|British Army}}

The British Army is the land force of the British Armed Forces, and is made up of the Regular Army and the part-time [[Army Reserve (United Kingdom)|Army Reserve]]. The Army is commanded by the [[Chief of the General Staff (United Kingdom)|Chief of the General Staff]], a [[four-star general]] within [[Army Headquarters (United Kingdom)|Army Headquarters]], based at [[Marlborough Lines|Andover]].<ref>{{Cite web |title=Command Structure |website= The British Army |url=https://www.army.mod.uk/who-we-are/our-people/command-structure/ |url-status=live |archive-url=https://web.archive.org/web/20231216063710/https://www.army.mod.uk/who-we-are/our-people/command-structure/ |archive-date= 16 December 2023 }}</ref>
[[File:ILauncher (within Sky Sabre).jpg|thumb|[[Sky Sabre]] (with ''Land Ceptor'' missiles) ground-based air defence system as operated by [[7th Air Defence Group]].]]
Deployable combat formations are;<ref>{{Cite web |title=Formations, Divisions & Brigades |website= The British Army |url=https://www.army.mod.uk/who-we-are/formations-divisions-brigades/ |url-status=live |archive-url=https://web.archive.org/web/20231216113424/https://www.army.mod.uk/who-we-are/formations-divisions-brigades/ |archive-date= 16 December 2023 }}</ref><ref name=":1">{{Cite web |title=Future Soldier: Transforming the British Army |url=https://www.gov.uk/government/publications/future-soldier-transforming-the-british-army |date=25 November 2021 |access-date=4 December 2023 |website=GOV.UK |language=en}}</ref>

* [[1st (United Kingdom) Division|1st (UK) Division]], consisting of [[16 Air Assault Brigade Combat Team]] and four other Light or Light Mechanised Brigade Combat Teams, with supporting engineering, logistic, intelligence and signals units.<ref name=":0">{{Cite web |date=31 July 2019 |title=Army restructures to confront evolving threats |url=https://www.gov.uk/government/news/army-restructures-to-confront-evolving-threats |access-date=4 December 2023 |website=GOV.UK |language=en}}</ref>
* [[3rd (United Kingdom) Division|3rd (UK) Division]], consisting of [[3rd Deep Reconnaissance Strike Brigade]], [[7th Air Defence Group|7 Air Defence Group]], and two Armoured Brigade Combat Teams, with supporting engineering, logistic, intelligence and signals units.<ref name=":0" />
* [[Field Army Troops]], consisting of the new [[Ranger Regiment (United Kingdom)|Ranger Regiment]], in [[Army Special Operations Brigade]]; Security Force Assistance Brigade and [[77th Brigade (United Kingdom)|77 Brigade]], a [[Psychological warfare|psychological operations]] unit.<ref name=":0" />
[[File:Boxer MIV on 2019 Army Combat Power Demonstration (ACPD) - 9.jpg|thumb|[[Boxer (armoured fighting vehicle)|Boxer]] [[Mechanised Infantry Vehicle|mechanised infantry vehicle]] (MIV) with [[remote weapon station]] (RWS).]]
The [[Infantry of the British Army]] has a strength of 48 battalions (32 regular and 16 reserve), structured under 17 unique regiments.<ref>{{cite web | url=https://www.gov.uk/government/statistics/uk-armed-forces-equipment-and-formations-2023 | title=UK armed forces equipment and formations 2023 |website=GOV.UK |date=21 September 2023 |url-status=live |archive-url= https://web.archive.org/web/20240103143515/https://www.gov.uk/government/statistics/uk-armed-forces-equipment-and-formations-2023 |archive-date= 3 January 2024 }}</ref> These battalions are trained and equipped for specific roles within their respective Brigade Combat Teams (BCT); [[Light infantry|Light Infantry]], such as the famous 1st Battalion [[Grenadier Guards]], within the [[4th Light Brigade Combat Team]], fight on foot without armoured vehicles; [[Mechanized infantry|Light Mechanised Infantry]], such as the 1st Battalion [[Royal Yorkshire Regiment]], within the [[7th Light Mechanised Brigade Combat Team]], operate the [[Ocelot (vehicle)|Foxhound]] protected mobility vehicle; Armoured Infantry (to become Heavy Mechanised Infantry under [[Future Soldier (British Army)|Future Soldier]]), such as the 1st Battalion [[Royal Regiment of Fusiliers]], within the [[20th Armoured Brigade Combat Team (United Kingdom)|20th Armoured Infantry Brigade Combat Team]], operate the [[Warrior tracked armoured vehicle|Warrior]] infantry fighting vehicle (IFV), but will be equipped with the new [[Boxer (armoured fighting vehicle)|Boxer]] mechanised infantry vehicle from 2024.<ref>{{Cite web |title=Infantry |website= The British Army |url=https://www.army.mod.uk/who-we-are/corps-regiments-and-units/infantry/ |url-status=live |archive-url=https://web.archive.org/web/20231212180557/https://www.army.mod.uk/who-we-are/corps-regiments-and-units/infantry/ |archive-date= 12 December 2023 }}</ref><ref name=":1" /><ref>{{Cite web |last=ERR |first=Joakim Klementi {{!}} |date=23 October 2023 |title=Brigade assigned to Estonia likely to be one of British Army's strongest |url=https://news.err.ee/1609141828/brigade-assigned-to-estonia-likely-to-be-one-of-british-army-s-strongest |access-date=4 December 2023 |website=ERR |language=en}}</ref>
[[File:B Company 2 Battalion the Parachute Regiment MOD 45167489.jpg|thumb|[[2nd Battalion, Parachute Regiment|2PARA]] on a [[live fire exercise]] operating the [[Javelin ATGM|Javelin anti-tank guided missile]], [[FN MAG|GPMG]], and [[Heckler & Koch GMG|GMG]] from a [[Land Rover Wolf|RWMIK]].]]
The four battalions of the [[Parachute Regiment (United Kingdom)|Parachute Regiment]], forming [[16 Air Assault Brigade Combat Team]] and part of [[Special Forces Support Group]], are the British Army's elite airborne infanteers, held at high readiness and specialising in rapid deployment by parachute and helicopter, widely regarded as the "fittest, most aggressive, resilient and disciplined regiment in the British Army."<ref>{{Cite news |last=Betts |first=Nick |date=9 January 2019 |title=Inside the Parachute Regiment, 'the last outpost for hard men willing to do bad things to bad people' |language=en-GB |work=The Telegraph |url=https://www.telegraph.co.uk/men/the-filter/inside-parachute-regiment-last-outpost-hard-men-willing-do-bad/ |access-date=4 December 2023 |issn=0307-1235}}</ref><ref>{{Cite web |title=The Parachute Regiment {{!}} National Army Museum |url=https://www.nam.ac.uk/explore/paras |access-date=4 December 2023 |website=www.nam.ac.uk |language=en}}</ref><ref>{{Cite web |title=Special Forces Support Group {{!}} SFSG |url=https://www.eliteukforces.info/sfsg/ |access-date=4 December 2023 |website=www.eliteukforces.info}}</ref><ref>{{Cite web |date=20 September 2011 |title=BBC Four - Regimental Stories, The Parachute Regiment, An Introduction to The Parachute Regiment |url=https://www.bbc.co.uk/programmes/p00kkqhg |access-date=4 December 2023 |website=BBC |language=en-GB}}</ref>

The [[Royal Armoured Corps]] provides the armoured capability of the British Army. The [[Royal Tank Regiment]], [[Queen's Royal Hussars]] and [[Royal Wessex Yeomanry]] (of the [[Army Reserve (United Kingdom)|Army Reserve]]) operate [[Challenger 2]] main battle tanks, which are being upgraded to [[Challenger 3]], and are part of [[3rd (United Kingdom) Division|3rd (UK) Division]]'s Armoured Brigade Combat Teams. Armoured Cavalry regiments, such as the [[Royal Dragoon Guards]], currently operate the [[Warrior tracked armoured vehicle|Warrior IFV]] on an interim basis, until [[General Dynamics Ajax|Ajax]] reaches [[full operating capability]]. There are six Light Cavalry regiments (three Regular + three Reserve) equipped with the [[Jackal (vehicle)|Jackal 2]] and [[Jackal (vehicle)#Coyote|Coyote TSV]], tasked with providing reconnaissance and fire support. The [[Household Cavalry]], made up of the [[Life Guards (United Kingdom)|Life Guards]] and the [[Blues and Royals]], operate in a dual role of Armoured Cavalry and Mounted Ceremonial on [[Horse Guards (building)|Horse Guards]] in London, and for state occasions.<ref>{{Cite web |title=Ceremonial |url=https://www.hcavfoundation.org/about/about-the-household-cavalry/ceremonial/ |access-date=4 December 2023 |website=Household Cavalry |language=en-US}}</ref><ref>{{Cite web |title=The Royal Dragoon Guards {{!}} National Army Museum |url=https://www.nam.ac.uk/explore/royal-dragoon-guards |access-date=4 December 2023 |website=www.nam.ac.uk |language=en}}</ref><ref>{{Cite web |title=Squadrons |url=https://royaltankregiment.com/what-we-do/squadrons/ |access-date=4 December 2023 |website=Royal Tank Regiment |date=9 September 2020 |language=en-GB}}</ref><ref name=":1" /><ref>{{Cite web |title=Royal Armoured Corps |website= The British Army |url=https://www.army.mod.uk/who-we-are/corps-regiments-and-units/royal-armoured-corps/ |url-status=live |archive-url=https://web.archive.org/web/20231215212336/https://www.army.mod.uk/who-we-are/corps-regiments-and-units/royal-armoured-corps/ |archive-date= 15 December 2023 }}</ref>

===Royal Air Force===
{{Main|Royal Air Force}}
[[File:Royal Air Force Eurofighter EF-2000 Typhoon F2 Lofting-1.jpg|thumb|The [[Eurofighter Typhoon]] [[multirole combat aircraft]]]]

The Royal Air Force has a large operational fleet that fulfils various roles, consisting of both [[List of active United Kingdom military aircraft|fixed-wing and rotary aircraft]].<ref>{{cite hansard|title=Military Aircraft|url=https://publications.parliament.uk/pa/cm201212/cmhansrd/cm120131/text/120131w0002.htm#120131143001971|house=House of Commons|date=31 January 2012|speaker=Nick Harvey|position=Minister of State for the Armed Forces|access-date=14 April 2019|archive-url=https://web.archive.org/web/20170917213512/https://publications.parliament.uk/pa/cm201212/cmhansrd/cm120131/text/120131w0002.htm#120131143001971|archive-date=17 September 2017|url-status=live}}</ref> Frontline aircraft are controlled by [[RAF Air Command|Air Command]], which is organised into five [[Group (air force)|groups]] defined by function: [[No. 1 Group RAF|1 Group]] (Air Combat), [[No. 2 Group RAF|2 Group]] (Air Support), [[No. 11 Group RAF|11 Group]] (Air and Space operations),<ref name="RAF">{{Cite web |url=http://www.raf.mod.uk/structure/ |title=RAF – Structure |access-date=20 February 2007 |archive-url=https://web.archive.org/web/20070221205633/http://www.raf.mod.uk/structure/ |archive-date=21 February 2007 |url-status=dead}}</ref> [[No. 22 Group|22 Group]] (training aircraft and ground facilities) and [[No. 38 Group RAF|38 Group]] (Royal Air Force's Engineering, Logistics, Communications and Medical Operations units).<ref name="RAF" /> In addition [[No. 83 Expeditionary Air Group (United Kingdom)|83 Expeditionary Air Group]] directs formations in the Middle East and the [[No. 38 Group RAF|38 Group]] combines the expeditionary [[Combat Support|combat support]] and [[Combat Service Support|combat service support]] units of the RAF. Deployable formations consist of Expeditionary Air [[Wing (air force unit)|Wings]] and [[Squadron (aviation)|squadrons]]—the basic unit of the Air Force.<ref>[http://www.raf.mod.uk/rafcms/mediafiles/628864A8_EC65_BEBF_C4C64EC02534493A.pdf Transforming the Royal Air Force] {{Webarchive|url=https://web.archive.org/web/20070610172134/http://www.raf.mod.uk/rafcms/mediafiles/628864A8_EC65_BEBF_C4C64EC02534493A.pdf |date=10 June 2007 }}, raf.mod.uk</ref><ref>[http://www.raf.mod.uk/structure/squadrons.cfm Royal Air Force Squadrons], raf.mod.uk {{webarchive |url=https://web.archive.org/web/20140219044631/http://www.raf.mod.uk/structure/squadrons.cfm |date=19 February 2014 }}</ref> Independent [[Flight (military unit)|flights]] are deployed to facilities in Brunei, the Falkland Islands, Iraq, and the United States.<ref>[http://www.scramble.nl/uk.htm Aircraft Order of Battle], Scramble (magazine) {{webarchive|url=https://web.archive.org/web/20120730094243/http://www.scramble.nl/uk.htm|date=30 July 2012}}</ref>

The Royal Air Force operates multi-role and single-role fighters, reconnaissance and patrol aircraft, tankers, transports, helicopters, unmanned aerial vehicles, and various types of training aircraft.<ref>[http://www.raf.mod.uk/equipment Royal Air Force – Equipment] {{Webarchive|url=https://web.archive.org/web/20070217000203/http://www.raf.mod.uk/equipment/ |date=17 February 2007 }}, raf.mod.uk</ref>

Ground units are also maintained by the Royal Air Force, most prominently the [[RAF Police]] and the [[Royal Air Force Regiment]] (RAF Regt). The Royal Air Force Regiment essentially functions as the ground defence force of the RAF, optimised for the specialist role of fighting on and around forward airfields, which are densely packed with operationally vital aircraft, equipment, infrastructure and personnel.<ref>[http://www.raf.mod.uk/structure/rafregiment.cfm The Royal Air Force Regiment], raf.mod.uk {{webarchive |url=https://web.archive.org/web/20121005150508/http://www.raf.mod.uk/structure/rafregiment.cfm |date=5 October 2012 }}</ref> The Regiment contains nine regular squadrons, supported by five squadrons of the [[Royal Auxiliary Air Force]] Regiment. In addition, it provides [[Forward air control|Forward Air Controllers]] to defence as well as a contribution to the [[Special Forces Support Group]].<ref>{{Cite web |title=Forward Air Controllers {{!}} British FAC {{!}} JTAC |url=https://www.eliteukforces.info/forward-air-controllers/ |access-date=4 December 2023 |website=www.eliteukforces.info}}</ref><ref>{{Cite web |title=Immersive Close Air Support Simulator delivered to British military - UPI.com |url=https://www.upi.com/Defense-News/2015/04/01/British-military-gets-simulator-training-system-from-Selex-ES/1751427897019/ |access-date=4 December 2023 |website=UPI |language=en}}</ref>

==Ministry of Defence==
{{Main|Ministry of Defence (United Kingdom)}}
[[File:RFA Argus, FS Meuse and RS Regina Maria at anchor in the Solent, in readiness for the International Fleet Review. MOD 45145024.jpg|thumb|{{ship|RFA|Argus|A135|6}} (left), the fleet's [[Flight training|aviation training]] and [[hospital ship]]]]

The Ministry of Defence maintains a number of civilian agencies in support of the British Armed Forces. Although they are civilian, they play a vital role in supporting Armed Forces operations, and in certain circumstances are under military discipline:

* The '''[[Royal Fleet Auxiliary]]''' (RFA) operates 11 ships which primarily serve to replenish Royal Navy warships at sea, and also provides an amphibious warfare capability through its three {{sclass2|Bay|landing ship dock}} vessels and the aviation support ship [[RFA Argus (A135)|RFA Argus]]. It is manned by 1,750 civilian personnel and is funded and run by the Ministry of Defence.
* The '''[[Ministry of Defence Police]]''' (MDP) has an established strength of 2,700 police officers which provide armed security, counter terrorism, uniformed policing and investigative services to Ministry of Defence property, personnel, and installations throughout the United Kingdom.
* The '''[[Defence Equipment and Support]]''' (DE&S) is the merged procurement and support organisation within the UK [[Ministry of Defence (United Kingdom)]]. It came into being on 2 April 2007, bringing together the MoD's [[Defence Procurement Agency]] and the [[Defence Logistics Organisation]] under the leadership of General Sir [[Kevin O'Donoghue]] as the first [[Chief of Defence Materiel]]. {{As of|2012}} it has a civilian and military workforce of approx. 20,000 personnel. DE&S is overseen by the [[Minister for Defence Equipment, Support and Technology]].
* The '''[[UK Hydrographic Office]]''' (UKHO) is an organisation within the [[UK government]] responsible for providing [[navigational]] and other hydrographic information for national, civil and defence requirements. The UKHO is located in [[Taunton]], [[Somerset]], on Admiralty Way and has a workforce of approximately 1,000 staff.

==Recruitment==
{{Further|Recruitment in the British Army}}
[[File:Royal Marine During Passing Out Parade MOD 45154046.jpg|thumb|A newly qualified [[Royal Marine]] of 122 Troop Kings Squad is pictured during a [[Passing out (military)|passing out parade]] in 2011, having undergone the recruitment process and selection and training]]
All three services of the British Armed Forces recruit primarily from within the United Kingdom, although citizens from the [[Commonwealth of Nations]] and the [[Republic of Ireland]] are equally eligible to join.<ref name="Times">Evans (2005), [http://www.timesonline.co.uk/tol/news/uk/article589974.ece How British Army is fast becoming foreign legion] {{Webarchive|url=https://web.archive.org/web/20100529145600/http://www.timesonline.co.uk/tol/news/uk/article589974.ece |date=29 May 2010 }}, timesonline.co.uk</ref> The minimum recruitment age is 16 years (although personnel may not serve on armed operations below 18 years, and if under 18 must also have parental consent to join); the maximum recruitment age depends whether the application is for a regular or reserve role; there are further variations in age limit for different corps/regiments. The normal term of engagement is 22 years; however, the minimum service required before resignation is 4 years, plus, in the case of the Army, any service person below the age of 18. A note to add is that in the United Kingdom, people may join the "Cadet Forces" such as the army cadets, Royal Air Force Air Cadets or the sea and Royal Marine Cadets. Young people may join these organisations which are either funded or affiliated with the MOD from the age of 13-18, there is no obligation to then join the armed forces however it teaches key skills in both civilian and military life and is a key recruitment drive for the armed forces.<ref>BBC News (6 January 2007), "[http://news.bbc.co.uk/1/hi/uk/6236345.stm Recruitment Age for Army Raised]". {{Webarchive|url=https://web.archive.org/web/20120208183807/http://news.bbc.co.uk/1/hi/uk/6236345.stm |date=8 February 2012 }}.</ref> At present, the yearly intake into the armed forces is 11,880 (per the 12 months to 31 March 2014).<ref name="PersonnelGOV">[https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/310468/quarterly_personnel_report_apr14.pdf UK Armed Forces Quarterly Personnel Report] {{Webarchive|url=https://web.archive.org/web/20140714204554/https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/310468/quarterly_personnel_report_apr14.pdf |date=14 July 2014 }}, gov.uk, 1 April 2014</ref>

Excluding the [[Brigade of Gurkhas]] and the [[Royal Irish Regiment (1992)|Royal Irish Regiment]], as of 1 April 2014 there are approximately 11,200 Black and Minority Ethnic (BME) persons serving as Regulars across the three service branches; of those, 6,610 were recruited from outside the United Kingdom. In total, Black and Minority Ethnic persons represent 7.1% of all service personnel, an increase from 6.6% in 2010.<ref name="PersonnelGOV" />

Since the year 2000, [[Sexual orientation and the military of the United Kingdom|sexual orientation has not been a factor considered in recruitment]], and homosexuals can serve openly in the armed forces. All branches of the forces have actively recruited at [[Gay Pride]] events.<ref>{{cite news|url=http://news.bbc.co.uk/1/hi/england/manchester/4189634.stm|title=Army marches with Pride parade|work=BBC News|date=27 August 2005|access-date=6 November 2009|archive-url=https://web.archive.org/web/20060218115212/http://news.bbc.co.uk/1/hi/england/manchester/4189634.stm|archive-date=18 February 2006|url-status=live}}</ref><ref>{{cite web|url=http://www.pridelondon.org/blog.php?b=1216 |title=The LGBT community in the Armed Forces |date=11 June 2008 |publisher=London Gay Pride official website |access-date=6 November 2009 |url-status=usurped |archive-url=https://web.archive.org/web/20140227165621/http://www.pridelondon.org/blog.php?b=1216 |archive-date=27 February 2014 }}</ref> The forces keep no formal figures concerning the number of gay and lesbian serving soldiers, saying that the sexual orientation of personnel is considered irrelevant and not monitored.<ref>{{cite news|url=http://www.timesonline.co.uk/tol/news/uk/article559936.ece|title=Army on parade for gay recruits|first=Jonathan|last=Leake|author2=Philip Cardy|newspaper=[[The Times]]|access-date=6 November 2009|date=28 August 2005|location=London|archive-url=https://web.archive.org/web/20100529145528/http://www.timesonline.co.uk/tol/news/uk/article559936.ece|archive-date=29 May 2010|url-status=dead}}</ref>

===Role of women===
{{Further|Women in the military by country#United Kingdom}}
[[File:Hrh Princess Elizabeth in the Auxiliary Territorial Service, April 1945 TR2832.jpg|thumb|right|[[Elizabeth II|Princess Elizabeth]] (later Queen Elizabeth II) in the [[Auxiliary Territorial Service]], April 1945]]
[[Women]] have been part of the armed forces, on and off, for centuries, more fully integrated since the early 1990s, including flying fast jets and commanding warships or artillery batteries. As of 1 April 2014, there were approximately 15,840 women serving in the armed forces, representing 9.9% of all service personnel.<ref name="PersonnelGOV"/> The first female military pilot was [[Flight Lieutenant]] [[Julie Ann Gibson]] while Flight Lieutenant [[Jo Salter]] was the first fast-jet pilot, the latter flying a Tornado GR1 on missions patrolling the then [[Iraqi no-fly zones|Northern Iraqi No-Fly Zone]].<ref>{{cite news|last=Haynes|first=Deborah|author-link=Deborah Haynes|date=23 May 2009|title=The Top Gun girl and the Tornado fast jet|work=[[The Times]]|location=London|url=https://www.thetimes.com/uk/defence/article/the-top-gun-girl-and-the-tornado-fast-jet-svdtwdzbm8b|url-status=live|url-access=subscription|access-date=31 March 2011|archive-url=https://web.archive.org/web/20110512175444/http://www.timesonline.co.uk/tol/life_and_style/court_and_social/article6344981.ece|archive-date=12 May 2011}}</ref> Flight Lieutenant Juliette Fleming and [[Squadron Leader]] Nikki Thomas recently{{when|date=February 2024}} were the first Tornado GR4 crew.<ref>[http://www.thisisdevon.co.uk/news/Tornados-Taliban-day-s-work-Nikki-navigator/article-1652922-detail/article.html Tornados and Taliban are all in a day's work] {{webarchive|url=https://web.archive.org/web/20110513182051/http://www.thisisdevon.co.uk/news/Tornados-Taliban-day-s-work-Nikki-navigator/article-1652922-detail/article.html |date=13 May 2011 }}. This is Devon (29 December 2009). Retrieved on 24 August 2013.</ref> While enforcing the Libyan No-Fly Zone, Flight Lieutenant Helen Seymour was identified as the first female Eurofighter Typhoon pilot.<ref>{{cite news|url=https://www.telegraph.co.uk/news/uknews/defence/8402845/First-woman-to-fly-Typhoon-enforces-no-fly-zone.html|location=London|work=The Daily Telegraph|first=Nick|last=Collins|title=First woman to fly Typhoon enforces no-fly-zone|date=24 March 2011|access-date=5 April 2018|archive-url=https://web.archive.org/web/20180211152403/http://www.telegraph.co.uk/news/uknews/defence/8402845/First-woman-to-fly-Typhoon-enforces-no-fly-zone.html|archive-date=11 February 2018|url-status=live}}</ref>

In August 2011, it was announced that a female lieutenant commander, [[Sarah West]], was to command the [[frigate]] {{HMS|Portland|F79|6}}.<ref>{{cite news|url=https://www.bbc.co.uk/news/uk-14444808|work=BBC News|title=Royal Navy appoints first female warship commander|date=8 August 2011|access-date=21 July 2018|archive-url=https://web.archive.org/web/20181112195203/https://www.bbc.co.uk/news/uk-14444808|archive-date=12 November 2018|url-status=live}}</ref> In July 2016, it was announced that women would be allowed to serve in close combat, starting with the Royal Armoured Corps.<ref>{{cite news|url=https://www.gov.uk/government/news/ban-on-women-in-ground-close-combat-roles-lifted|work=UK Ministry of Defence|title=Ban on women in ground close combat roles lifted|date=8 July 2016|access-date=15 July 2016|archive-url=https://web.archive.org/web/20160709150054/https://www.gov.uk/government/news/ban-on-women-in-ground-close-combat-roles-lifted|archive-date=9 July 2016|url-status=live}}</ref> In July 2017, the Secretary of Defence announced that women would be allowed to enlist in the [[RAF Regiment]] from September 2017, a year ahead of schedule.<ref>{{cite news|url=https://www.gov.uk/government/news/raf-opens-close-combat-role-to-women-ahead-of-schedule|work=UK Ministry of Defence|title=RAF opens close combat role to women ahead of schedule|date=13 July 2017|access-date=13 July 2017|archive-url=https://web.archive.org/web/20170728225958/https://www.gov.uk/government/news/raf-opens-close-combat-role-to-women-ahead-of-schedule|archive-date=28 July 2017|url-status=live}}</ref> In 2018, women were allowed to apply for all roles in the British military, including the [[United Kingdom Special Forces|special forces]].<ref>{{cite news |author=Lizzie Dearden Home Affairs Correspondent @lizziedearden |url=https://www.independent.co.uk/news/uk/home-news/women-soldiers-army-military-sas-defence-government-infantry-frontline-gavin-williamson-female-a8601371.html |title=Women now allowed to apply for Royal Marines and all other frontline military roles, defence secretary announces |newspaper=The Independent |access-date=25 October 2018 |archive-url=https://web.archive.org/web/20181025225835/https://www.independent.co.uk/news/uk/home-news/women-soldiers-army-military-sas-defence-government-infantry-frontline-gavin-williamson-female-a8601371.html |archive-date=25 October 2018 |url-status=live}}</ref> {{as of|2024|June|10}}, the [[List of senior female officers of the British Armed Forces|most senior serving woman]] is [[Four star rank|four-star]] General [[Sharon Nesmith|Dame Sharon Nesmith]].

== Music ==
{{Main|List of marches of the British Armed Forces}}

==See also==
{{Portal|United Kingdom|Aviation}}
* [[Armed Forces Day (United Kingdom)]]
* [[List of military equipment of the United Kingdom]]
* [[Atholl Highlanders]] – The only legal [[private army]] in Europe under the command of the [[Duke of Atholl]] in [[Scotland]]
* [[Banknotes of the British Armed Forces]]
* [[British Forces Broadcasting Service]]
* [[Community Cadet Forces]]
* [[Military Covenant]] – The mutual obligations between the nation and its Armed Forces.
* [[Network-enabled capability]] – British military concept of achieving enhanced military effect through the better use of [[information systems]]. Similar to the US concept of [[network-centric warfare]].
* [[The Championships, Wimbledon#Services stewards]]
* [[Uniforms of the British Armed Forces]]
* [[Military history of Scotland]]
* [[Armed forces in Scotland]]
* [[Armed forces in Wales]]

==Notes==

{{notelist}}

==References==
{{Reflist}}

==External links==
{{Commons category|Military of the United Kingdom}}
{{wiktionary|Appendix:Glossary of British military slang and expressions}}
* [https://www.gov.uk/government/organisations/ministry-of-defence British Ministry of Defence] (gov.uk)
* [https://web.archive.org/web/20091204170712/http://da.mod.uk/mk Defence Academy of the United Kingdom] (.da.mod.uk)
* [http://www.royalnavy.mod.uk/ Royal Navy official website] (royalnavy.mod.uk)
* [http://www.royalnavy.mod.uk/our-organisation/the-fighting-arms/royal-marines Royal Marines official webpage] (royalnavy.mod.uk)
* [http://www.army.mod.uk/ British Army official website] (army.mod.uk)
* [http://www.raf.mod.uk/ Royal Air Force official website] (raf.mod.uk)

{{British Armed Forces}}
{{United Kingdom topics}}
{{British Military}}
{{Military of Europe}}
{{North Atlantic Treaty Organization}}

[[Category:British Armed Forces| ]]
[[Category:Military of the United Kingdom| ]]
[[Category:British Armed Forces deployments|British Armed Forces deployments]]