Eusebius (AD c. 260-339) was a Greek Christian writer, often called the 'Father of Ecclesiastical History'. He was born in Palestine and educated at Caesarea, the city of which he later became bishop. Eusebius' voluminous literary remains may be grouped into four categories: the historical, the apologetic, the Biblical and the dogmatic. The Ecclesiastical History comprises ten books, covering the period from the foundation of the Church to the defeat of Licinius in 324. A Preparation for the Gospel, in fifteen books, shows that Christians rightly prefer Judaism to paganism, and its continuation, the Proof of the Gospel, shows how Christian religion is the fulfillment of the Old Testament. Among Eusebius' other works are the Onomasticon, gazetteer of Bible sites, Commentary on the Psalms, of which only fragments remain, and the two books Against Marcellus. Sometimes termed the 'Christian Herodotus', Eusebius has earned legitimate fame as the historian of Christian antiquity.
Eusebius' account is the only surviving historical record of the Church during its crucial first 300 years. Bishop Eusebius, a learned scholar who lived most of his life in Caesarea in Palestine, broke new ground in writing the History and provided a model for all later ecclesiastical historians. In tracing the history of the Church from the time of Christ to the Great Persecution at the beginning of the fourth century and ending with the conversion of the Emperor Constantine, his aim was to show the purity and continuity of the doctrinal tradition of Christianity and its struggle against persecutors and heretics. He also supported his account by extensive quotations from original sources.
Eusebius, The History of the Church 1989