Constantine the Great

Constantine I, called the Great (c. 272–337), was the Roman emperor who ended the Tetrarchy, favoured Christianity and founded Constantinople. Born at Naissus, son of Constantius and Helena, he was raised at Diocletian’s court; passed over at Diocletian’s abdication in 305, he joined his father in Britain and was hailed Augustus in 306.

In 312 he defeated Maxentius at the Milvian Bridge, where Eusebius records a vision of the Chi Rho. In 313 he and Licinius issued the Edict of Milan, allowing Christians to worship freely. He ruled alone from 324, summoned the Council of Nicaea in 325 and in 330 dedicated Byzantium as his new capital, Constantinople.

In 326 he had his eldest son Crispus put to death and wife Fausta killed in an overheated bath. He fell ill in 337 and was baptized only on his deathbed, leaving the empire to his three sons by Fausta.