Eusebius of Caesarea (circa 260-340 A.D.), studied under Bishop Pamphilius of Caesarea, who was at that time the foremost authority on the Bible, closely following the teachings of Origen. During the Great Persecution of Christians started by Emperor Diocletian in 303, Eusebius began accumulating what would later become his magnum opus, Historia Ecclesiastica, salvaging many Christian manuscripts from obliteration. Although Eusebius himself survived the Great Persecution, his teacher Pamphilius would be imprisoned and eventually martyred.
Eusebius lived during a tumultuous time even within the early Christian Church itself. He was engaged in many theological controversies, but fortunately for him he would become the leading spiritual advisor to the Emperor Constantine after his Christian conversion, and was thereby personally exonerated for his views on more than one occasion.
He died as the Bishop of Caesarea, declining a promotion as Bishop of Antioch. For his prudence in preserving many Christian manuscripts of first three centuries he became known as The Father of Church History.
