(260-341 A. D.) Eusebius Pamphili, Bishop of Cæsarea in Palestine, known as the "Father of Church History". Known to have been counsel to Emperor Constantine who converted the Roman Empire to Christianity. Was an anti-Gnostic,who carried on the teachings of Irenaeus, and Hippolytus against heretics. "At the opening of the Council of Nicæa Eusebius occupied the first seat on the right of the emperor, and delivered the inaugural address which was couched in a strain of thanksgiving to Almighty God on his, the emperor's behalf". (New Advent, Catholic Encyc., Online.) http://www.earlychurch.org.uk/eusebius.php