Centuries: 3rd century - 4th century - 5th century
- May 11 - Constantine I refounds Byzantium, renames it New Rome, and moves the capital of the Roman Empire there from Rome. It is later known as Constantinople.
- Frumentius is the first bishop of Ethiopia (approximate date).
- Eustathius, patriarch of Antioch, is banished to Trajanopolis
- Basil of Caesarea, Eastern Orthodox saint (approximate date)
- St. Moses the Black, Christian monk
- Saint Macrina the Younger, Christian nun