This Day in World History
October 28, 312 CE
Constantine wins control of Roman Empire
Control of the Roman Empire was in the balance when the armies of Constantine and his brother-in-law Maxentius clashed near the Milvian Bridge, north of Rome. Despite having a smaller army, Constantine triumphed—a victory made secure when Maxentius drowned in the Tiber River while trying to escape. Constantine’s victory left him in command of the western half of the Roman Empire—but it also had more significant consequences.
After the battle, Constantine claimed that his success was due to his decision to embrace Christianity. Histories composed a few years later promoted the story that before the battle the emperor received an omen in which he beheld a vision of the Christian cross with the encouraging words, ‘Conquer in this sign”. While those accounts are not necessarily reliable and scholars still debate Constantine’s religious beliefs, the triumphal arch that Constantine built in Rome three years after the battle shows him holding a cross in the air and bears the inscription, “By this saving sign I have delivered your city from the tyrant and restored liberty”—evidence that Constantine committed himself to the Christian cause (even if he did not become baptized until just before his death). In 313 CE, he and the Eastern emperor, Licinius, issued a proclamation from Milan that proclaimed toleration of all religions. Some earlier emperors had promised to refrain from persecuting Christians, but Constantine’s long reign—he remained emperor until 337, ruling alone after his defeat of Licinius in 324 CE—firmly entrenched this new of policy of toleration across the empire.