Centuries: 4th century - 5th century - 6th century
- August 3 - The Second Council of Ephesus opens, chaired by Dioscorus, Patriarch of Alexandria. Flavian, Patriarch of Constantinople is deposed.
- October, a Roman synod repudiates all the decisions of the Second Council of Ephesus.
- Anatolius becomes Patriarch of Constantinople
- Vortigern forms an alliance with Hengest and Horsa, by tradition chieftains of the Jutes, who led the Anglo-Saxon invasion of Britain. (traditional date)