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.

Life of Constantine the Great is a panegyric written in Greek in honor of Constantine the Great by Eusebius of Caesarea in the 4th century AD. It was never completed due to the death of Eusebius in 339. The work provides scholars with one of the most comprehensive sources for the religious policies of Constantine's reign. In addition to detailing the religious policies of the Roman Empire under Constantine, Eusebius uses Life of Constantine to engage several of his own religious concerns, such as apologetics, as well as a semi-bibliographic account of Constantine.