670

Year 670 (DCLXX) was a common year starting on Tuesday of the Julian calendar, the 670th year of the Common Era (CE) and Anno Domini (AD) designations, the 670th year of the 1st millennium, the 70th year of the 7th century, and the 1st year of the 670s decade. The denomination 670 for this year has been used since the early medieval period, when the Anno Domini calendar era became the prevalent method in Europe for naming years.

Events

Arab-Byzantine War: The Arab fleet dominates the Aegean Sea and conquers the strategic islands, Rhodes, Cos and Chios. The shore on the southern part of Sea of Marmara is taken, providing an excellent base at Cyzicus to begin the blockade of Constantinople by sea.<ref>John Cairns, "Road to Manzikert" (2012). Byzantine Warfare in an Age of Crisis and Recovery (Chapter 3), p. 67. Template:ISBN</ref>

February 15 – King Oswiu of Northumbria dies during a pilgrimage to Rome in the company of bishop Wilfrid.Template:Sfn He is succeeded by his son Ecgfrith, while his youngest son Ælfwine becomes king of Deira. Oswiu is buried at Whitby Abbey, alongside Edwin of Northumbria.

Muslim Conquest: A 10,000-man Arab army under the command of general Uqba ibn Nafi invades the Byzantine Exarchate of Africa. He establishes a military base at Kairouan (Tunisia) for further invasions, and founds the Great Mosque, also known as the "Mosque of Uqba".

April 2 - Hasan Ibn Ali, dies at 44.

Battle of Dafei River: Chinese forces (80,000 men), under general Xue Rengui of the Tang dynasty, are annihilated by the Tibetans, who take over control of the Tarim Basin.
A Goguryeo restoration movement, led by Geom Mojam in northern Korea, places Anseung on the throne. Geom is later murdered, and Anseung flees to neighboring Silla.
Tarumanagara (modern Indonesia) is divided into two kingdoms (Sunda Kingdom and Galuh Kingdom), with the Citarum River as the boundary (approximate date).
A family register, Kogo-nenjaku, is prepared in Japan (approximate date) ^{[Significance of this event is unclear]}.

Hōryū-ji, a Japanese Buddhist temple, burns to the ground after being hit by lightning; its reconstruction is immediately begun.
The diocese of Dorchester-on-Thames in England is replaced by the Diocese of Winchester (approximate date).