to remove each other, Constantine would eventually become sole emperor of the entire Roman Empire.
In 312, Constantine invaded Rome in order to take control of the Western Empire by defeating Maxentius, who had taken power in Italy and North Africa. Two other emperors had previously attempted to force Maxentius from power, but both had failed. Eusebius, a historian and Bishop of Caesarea, reports that Constantine saw a vision from God while he marched to Italy with his army. In the vision, a cross of light was set across the sun, with the words, "In this sign conquer" (Latin: in hoc signo vinces). Later, Constantine had a dream in which Christ promised him victory if Constantine would follow Christ. According to Eusebius, Constantine did so before joining battle with the army of Maxentius outside Rome. In the Battle of the Milvian Bridge, Constantine's army defeated the forces of Maxentius, and during a disorganized retreat Maxentius was drowned and his forces were defeated. Constantine entered Rome as liberator and proclaimed himself the sole emperor of the West. It is at this time that many historians, supported by Eusebius, believe that Constantine may have converted to Christianity. Soon after defeating Maxentius, Constantine issued the Edict of Milan, which granted tolerance for all religions and specifically mentioned Christianity.
While he was Emperor, Constantine attempted to settle major religious disputes that had developed within the Christian Church. Shortly after he defeated Maxentius, he was approached by the Christians of Africa, who asked him to settle a dispute between rival factions of the Donatist schism. Constantine attempted to reconcile the two sides, but he ultimately failed to end the schism. Constantine also attempted to unify the Arians