The Battle of the Milvian Bridge took place between the Roman Emperors Constantine I and Maxentius on 28 October 312 AD. It takes its name from the Milvian Bridge, an important route over the Tiber. Constantine won the battle and started on the path that led him to end the Tetrarchy and become the sole ruler of the Roman Empire. Maxentius drowned in the Tiber during the battle; his body was later taken from the river and decapitated, and his head was paraded through the streets of Rome on the day following the battle before being taken to Africa.

Eusebius of Caesarea, also known as Eusebius Pamphilus, was a Greek Syro-Palestinian historian of Christianity, exegete, and Christian polemicist. In about AD 314 he became the bishop of Caesarea Maritima in the Roman province of Syria Palaestina. Together with Pamphilus, he was a scholar of the biblical canon and is regarded as one of the most learned Christians during late antiquity. He wrote Demonstrations of the Gospel, Preparations for the Gospel and On Discrepancies between the Gospels, studies of the biblical text. As "Father of Church History", he produced the Ecclesiastical History, On the Life of Pamphilus, the Chronicle and On the Martyrs. He also produced a biographical work on Constantine the Great, the first Christian Roman emperor, who was Augustus between AD 306 and AD 337.