Events

• February 6 - Julius is elected pope.
• June 17 - Constantius II announces the restoration of Athanasius to the Patriarch of Alexandria.
• September 9 - Constantine II, Constantius II, and Constans succeed their father Constantine the Great as co-emperors of the Roman Empire.
• A number of descendants of Constantius I Chlorus, as well as powerful nobles, are executed. Responsibility for this purge is denied by the three Augusti.
• November 25 - Athanasius enters Alexandria.
• Paul I becomes Patriarch of Constantinople.
• Shapur II of Persia begins a war with the Roman Empire.

Births

• Fa-hsien, Chinese Buddhist monk and traveler (approximate date)

Deaths

• May 22 - Constantine I, Roman emperor
• September - Hannibalianus , King of the Pontus and grandson of Constantine I (executed)
• September - Dalmatius , Caesar and grandson of Constantine I (executed)
• September - Julius Constantius , son of Constantius I Chlorus and father of Julian (executed)
• September - Patricius Optatus (executed)
• September - Ablavius , Prefect of the Imperial Guard (executed)
• Eustathius, Patriarch of Antioch (probable date)
• Alexander, Patriarch of Constantinople