Constantine Defeats Maxentius at Milvian Bridge
Following the collapse of the Roman tetrarchy established by Diocletian, rival claimants vied for control of the western empire. Constantine marched into Italy to challenge Maxentius, who had seized Rome. On October 28, 312, their forces clashed near the Tiber River at the Milvian Bridge. Constantine's troops prevailed in the fierce engagement, forcing Maxentius and many of his soldiers into the river where the usurper drowned. Constantine entered Rome as victor the next day and soon consolidated power in the West. This outcome shifted the balance of imperial authority and set the stage for broader political and religious changes across the empire.
Why it matters: The victory ended a major phase of civil strife and positioned Constantine as the dominant western ruler. It directly influenced his later policies favoring Christianity, including the Edict of Milan in 313, which transformed the religion's status within the Roman world and shaped European history for centuries.