290s births

Pope of Alexandria from 328 to 373 (296–373)

4th century Greek mathematician

Flavius Julius Crispus (; 300 – 326) was the eldest son of the Roman emperor Constantine I, as well as his junior colleague (caesar) from March 317 until his execution by his father in 326. The grandson of the augustus Constantius I, Crispus was the elder half-brother of the future augustus Constantine II and became co-caesar with him and with his cousin Licinius II at Serdica, part of the settlement ending the Cibalensean War between Constantine and his father's rival Licinius I. Crispus ruled from Augusta Treverorum (Trier) in Roman Gaul between 318 and 323 and defeated the navy of Licinius

4th-century Roman empress and wife of Licinius

Saint Ansanus () (died 304 AD), called The Baptizer or The Apostle of Siena, is the patron saint of Siena, Italy and a scion of the Anician family of Rome.