The Hagia Sophia is completed.

In Constantinople, the dome of the Hagia Sophia collapses. Justinian I immediately orders that the dome be rebuilt.

The Byzantine church Hagia Sophia in Constantinople is dedicated for the second time after being destroyed by earthquakes.

Three Roman legates break relations between Western and Eastern Christian Churches through the act of placing an invalidly-issued Papal Bull of Excommunication on the altar of Hagia Sophia during Saturday afternoon divine liturgy. Historians frequently describe the event as the start of the East-West Schism.