1520

May 22: Aztec warriors and nobles are massacred by the Spaniards at Tenochtitlan

June 30–July 1: Hundreds of Spanish conquistadors are killed by Aztec warriors during La Noche Triste

Year 1520 (MDXX) was a leap year starting on Sunday of the Julian calendar.

Events

November 8: Stockholm Bloodbath

January–March

• January 19 – King Christian II of Denmark and Norway defeats the Swedes, at Lake Åsunden in Sweden. The Swedish regent Sten Sture the Younger is mortally wounded in the Battle of Bogesund. He is rushed towards Stockholm, in order to lead the fight against the Danes from there.<ref name=Butler>Template:Cite book</ref>
• February 3 – Swedish regent Sten Sture dies from his wounds leaving a vacancy on the throne that allows King Christian II of Denmark to conquer Sweden within eight months.<ref name=Butler/>
• February 6 – The Swabian League sells the Duchy of Württemberg to the Holy Roman Emperor, Charles V, for 220,000 florins and payment of the Duchy's debt of 1,100,000 Goldgulden<ref>Template:Cite book</ref>
• March 10 – Thomas Howard, 3rd Duke of Norfolk becomes England's new Lord Deputy of Ireland<ref>Template:Cite DNB</ref>
• March 31 – The Magellan expedition, led by Portuguese explorer Ferdinand Magellan (Fernão de Magalhães), pauses in its attempt to sail around the world, stopping at Puerto San Julian on the lower east coast of what is now Patagonia in Argentina. His fleet consists of Magellan's flagship, Trinidad, and four other vessels, Concepción, Victoria, San Antonio and Santiago.<ref>Template:Cite book</ref>

April–June

• April 2 – Juan de Cartagena, formerly captain of the largest ship on the Magellan expedition, San Antonio, escapes captivity from the Victoria and begins a mutiny against Ferdinand Magellan.<ref name=Beaglehole>Template:Cite book</ref> He is joined by Gaspar de Quesada, captain of the Concepción, and Luis de Mendoza, captain of the Victoria. On the first day of the rebellion, under the pretense of delivering Magellan's letter of surrender to the Victoria, several crew from the Magellan's flagship Trinidad stab Mendoza to death, and the rest of the Victoria crew seizes the mutineers.<ref name=Beaglehole/>
• April 3 – The crew of the San Antonio surrenders to Magellan after being unable to stop drifting in strong winds and being fired at by a cannon, and Gaspar de Quesada surrenders the Concepcion.<ref name=Beaglehole/> Four days later, Quesada is beheaded along with other mutineers, while Cartagena is left on an island by Magellan in August.
• April 16 – Revolt of the Comuneros: Citizens of Toledo, Castile opposed to the rule of the Flemish-born Charles V, Holy Roman Emperor, rise up when the royal government attempts to unseat radical city councilors.<ref>Template:Cite book</ref>
• May 7 – The semi-independent Duchy of Mecklenburg, in what is now Germany, is partitioned into two duchies, Mecklenburg-Schwerin and Mecklenburg-Strelitz.<ref>Gustav Hempel, Geographisch-statistisch-historisches Handbuch des Meklenburger Landes (Güstrow Frege, publisher, 1837), p. 52–53.</ref>
• May 22 –
  • The Massacre in the Great Temple of Tenochtitlan takes place in Mexico after the Aztec Emperor Moctezuma II is allowed by the Deputy Governor of New Spain, Pedro de Alvarado, to host Aztec nobles at the Great Temple at Tenochtitlan to celebrate the Feat of Toxcatl in honor of the god Tezcatlipoca. Alvarado uses the opportunity to kill more than 600 Aztec warriors and commanders, but spares Moctezuma.<ref name="Tena 2008">Template:Cite book</ref><ref name="Martinez 1994">Template:Cite journal</ref>
  • The Magellan expedition loses its first ship as the caravel Santiago is wrecked in a storm while sailing inland on Argentina's Santa Cruz River<ref name=Bergreen>Template:Cite book</ref>
• June 7 – King Henry VIII of England and King Francis I of France meet at the famous Field of the Cloth of Gold.<ref>Template:Cite book</ref>
• June 10 – Revolt of the Comuneros: Segovia is blockaded.
• June 15 – Pope Leo X issues the bull Exsurge Domine (Arise O Lord), threatening Martin Luther with excommunication, if he does not recant his position on indulgences and other Catholic doctrines.<ref>Template:Cite book</ref>
• June 29 – Moctezuma II, Aztec ruler of Tenochtitlan, is assassinated by other Aztec leaders as he attempts to address his people.<ref>Template:Cite book</ref> His brother Cuitláhuac rises to the throne.

July–September

• July 1 – La Noche Triste (Night of Sorrow): The forces of Cuitláhuac, Aztec ruler of Tenochtitlan, gain a major victory against the forces of conquistador Hernán Cortés. This results in the death of about 400 conquistadors, and some 2,000 of their Native American allies. However, Cortés and the most skilled of his men manage to escape and later regroup.
• July 7 – Otumba near Lake Texcaco: The Spaniards defeat the Aztecs.<ref>Template:Cite book</ref>
• August 11 – Ferdinand Magellan maroons the two surviving people who had attempted a mutiny against him, Captain Juan de Cartagena and Father Pedro Sánchez de la Reina, placing them on an island off of the coast of Argentina and providing them with a small supply of ship's biscuits and drinking water. Cartagena and Sanchez are never heard from again.<ref name=Beaglehole/>
• August 21 – After wintering in Patagonia in Argentina, the Magellan expedition resumes its attempt to become the first crew to sail around the world.<ref name=bergreen>Template:Cite book</ref>
• August 24 – The French warrior René of Savoy departs from Marseille on his flagship, Sainte Marie de Bonaventure on a four-month mission to protect the Knights Hospitaller against an attack by the Ottoman Turks.
• August – Martin Luther publishes To the Christian Nobility of the German Nation.<ref>Template:Cite book</ref>
• September 7 – Christian II makes his triumphant entry into Stockholm, which had surrendered to him a few days earlier.<ref>Template:Cite book</ref> Sten Sture's widow Christina Gyllenstierna, who has led the fight after Sten's death, and all other persons in the resistance against the Danes, are granted amnesty and are pardoned for their involvement in the resistance.
• September 22 – Suleiman I succeeds his father Selim I as Sultan of the Ottoman Empire.<ref>Template:Cite book</ref> He is officially crowned on September 30.<ref>Template:Cite book</ref>

October–December

• October 21 (Feast of St. Ursula) – The islands of Saint Pierre and Miquelon are discovered by Portuguese explorer João Álvares Fagundes, off Newfoundland. He names them Islands of the 11,000 Virgins, in honour of Saint Ursula.
• October 23 – Charles V is crowned King of Germany in Aachen.<ref>Template:Cite book</ref>
• October 21 – The four remaining ships of the Magellan expedition and their crews confirm that they have found the passage that will be named the Strait of Magellan, the passage between the Atlantic and Pacific Oceans. The crew of the San Antonio, led by Estêvão Gomes elects not to sail into strait and begins journeying back to Spain.<ref>Template:Cite book</ref>
• November 1 – Christian II is crowned king of Sweden in Nikolai Church.<ref>Template:Cite book</ref> The coronation is followed by a three-day feast in Stockholm.
• November 7 – At the end of the third day of Christian's coronation feast, several leading figures of the Swedish resistance against the Danish invasion are imprisoned, and tried for high treason.<ref>Template:Cite book</ref>
• November 9– Stockholm Bloodbath: The execution of 82 Swedish noblemen and clergymen, having been sentenced to death for their involvement in the Swedish resistance against the Danish invasion, is completed after two days of beheading.<ref>Template:Cite web</ref>
• November 25 – Cuauhtémoc becomes the last Aztec Emperor after the death from smallpox of the Emperor Cuitláhuac, who reigned for only 80 days.Template:Cite book
• November 28 – After navigating through the strait at the southern end of South America, three ships under the command of Portuguese explorer Ferdinand Magellan reach the Pacific Ocean. Magellan thankful to find a peaceful sea after the dangerous trip through the strait, names the body of water "El Mar Pacifico" because of its pacifying waters.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> becoming the first Europeans to sail from the Atlantic Ocean to the Pacific (the strait is later named the Strait of Magellan).
• December 10 – Martin Luther burns a copy of The Book of Canon Law (see Canon Law), and his copy of the Papal bull Exsurge Domine.<ref>Template:Cite book</ref>

Date unknown

• The Franciscan friar Matteo Bassi is inspired to return to the primitive life of solitude and penance, as practiced by St. Francis, giving rise to the Order of Friars Minor Capuchin.
• Duarte Barbosa returns to Cananor.
• Aleksandra Lisowska (Roxelana) is given as a gift to Suleiman I on the occasion of his accession to the throne.<ref>Template:Cite book</ref>
• King Manuel I creates the public mail service of Portugal, the Correio Público.<ref>Template:Cite news</ref>

Births

Barbara Radziwiłł

• January 7 – Peder Oxe, Danish finance minister (d. 1575)<ref>Template:Cite book</ref>
• January 30 – William More, English courtier (d. 1600)<ref>Template:Cite ODNB</ref>
• February 22 – Frederick III of Legnica, Duke of Legnica (d. 1570)
• March 3 – Matthias Flacius, Croatian Protestant reformer (d. 1575)<ref>Template:Cite book</ref>
• June 29 – Nicolás Factor, Spanish artist (d. 1583)<ref>Template:Cite book</ref>
• July 27 – Gonzalo II Fernández de Córdoba, Governor of the Duchy of Milan (d. 1578)<ref>Template:Cite book</ref>
• August 1 – King Sigismund II Augustus of Poland (d. 1572)<ref>Template:Cite book</ref>
• August 10 – Madeleine of Valois, queen of James V of Scotland (d. 1537)<ref>Template:Cite book</ref>
• August 21 – Bartholomäus Sastrow, German official (d. 1603)<ref>Template:Cite book</ref>
• August 31 – Heinrich Sudermann, German politician (d. 1591)<ref>Template:Cite book</ref>
• September 13 – William Cecil, 1st Baron Burghley, English statesman, chief advisor to Queen Elizabeth I (d. 1598)<ref>Template:Cite book</ref>
• October 7 – Alessandro Farnese, Italian cardinal (d. 1589)<ref>Template:Cite book</ref>
• November 10 – Dorothea of Denmark, Electress Palatine, Princess of Denmark, Sweden and Norway (d. 1580)<ref>Template:Cite book</ref>
• December 6 – Barbara Radziwiłł, queen of Poland (d. 1551)<ref>Template:Cite book</ref>
• December 24 – Martha Leijonhufvud, politically active Swedish noble (d. 1584)<ref>Template:Cite web</ref>
• date unknown
  • Patriarch Metrophanes III of Constantinople (d. 1580)
  • Jean Ribault, French navigator (d. 1565)<ref>Template:Cite book</ref>
  • Vincenzo Galilei, Italian music theorist, lutenist, and composer (d. 1591)<ref>Template:Cite book</ref>
  • Aben Humeya, last independent king of Granada (d. 1568)
  • Ijuin Tadaaki, Japanese nobleman (d. 1561)
  • Agatha Streicher, German physician (d. 1581)<ref>Template:Cite web</ref>
  • Katarina Bengtsdotter Gylta, Swedish abbess (d. 1593)<ref>Template:Cite web</ref>
  • Johannes Acronius Frisius, German doctor and mathematician (d. 1564)<ref>Template:Cite book</ref>
• probable
  • Hans Eworth, Flemish portrait painter (d. 1574)<ref>Template:Cite book</ref>
  • Katharina Gerlachin, German printer (d. 1592)
  • Jorge de Montemor, Spanish novelist and poet (d. 1561)<ref>Template:Cite book</ref>
  • Giovanni Battista Moroni, Italian mannerist painter (d. 1578)<ref>Template:Cite web</ref>

Deaths

Raphael

• January 10 – Cho Kwangjo, Korean philosopher (b. 1482)
• February 3 – Sten Sture the Younger, Viceroy of Sweden (b. 1493)<ref>Template:Cite book</ref>
• February 7 – Alfonsina de' Medici, née Orsini, Regent of Florence (b. 1472)<ref>Template:Cite book</ref>
• April 6 – Raphael, Italian painter and architect (b. 1483)<ref>Template:Cite book</ref>
• May 22 – Jan Lubrański, Polish bishop (b. 1456)<ref>Template:Cite book</ref>
• June 24 – Hosokawa Sumimoto, Japanese samurai commander (b. 1489)
• June 29 – Moctezuma II, 9th Tlatoani (emperor) of the Aztecs, assassinated or possibly killed in a riot, 1502-1520 (b. 1466)<ref>Template:Cite web</ref>
• August 6 – Kunigunde of Austria, Archduchess of Austria (b. 1465)<ref>Template:Cite book</ref>
• September 3 – Ippolito d'Este, Italian Catholic cardinal (b. 1479)<ref>Template:Cite book</ref><ref>Template:Cite journal</ref>
• September 22 – Selim I, Ottoman Sultan (b. 1470)<ref>Template:Cite book</ref>
• October – Cuitláhuac, 10th Tlatoani (emperor) of the Aztecs, 1520, brother of Moctezuma II, smallpox (b. c. 1476)<ref>Template:Cite web</ref>
• November 9 – Bernardo Dovizi, Italian Catholic cardinal (b. 1470)<ref>Template:Cite book</ref>
• date unknown
  • Cacamatzin, king of Texcoco (altepetl) (modern Mexico) (b. 1483)<ref>Template:Cite web</ref>
  • Ratna Malla, first Raja of Kantipur<ref>Template:Cite book</ref>
  • Visoun, king of Lan Xang (b. 1465)<ref>Template:Cite book</ref>
  • Sheikh Hamdullah, Ottoman calligrapher (b. 1436)<ref>Template:Cite book</ref>
  • Clara Tott, German court singer (b. 1440)
• probable – Filippo de Lurano, Italian composer (b. 1475)<ref>Template:Cite web</ref>