Constantine rebuilt the city of Byzantium and renamed the city Nova Roma (New Rome), providing it with a Senate and civic offices similar to the older Rome. He earned his place as ruler of the Roman Empire by defeating Maxentius at the Battle of Milvian Bridge in 312. Following this, he became Western Augustus, ruler of the entire Western Roman Empire until his death in 337.
He is best remembered for being the first Roman Emperor to embrace Christianity. He is also remembered for issuing the Edict of Milan in 313, which fully legalized Christianity in the Roman Empire for the first time. He also presided over the Council of Nicaea in 325. These actions are considered major factors in the spread of Christianity.