Eusebius of Caesarea; Eusebius Pamphili
Bishop of Caesarea in Palestine.
He made the acquaintance of Pamphilus, the founder of the magnificent library which remained for several centuries the glory of the Church of Caesarea, assisted in editing the Septuagint, and when Pamphilus was beheaded in the persecution of Diocletian assumed the name Eusebius Pamphili.
Already a bishop in 315, he delivered the inaugural address at the Council of Nicaea, but subscribed to its uncompromising creed only after some delay, and took part in the subsequent opposition to Saint Athanasius.
His works include lives of Pamphilus and Constantine, the monumental Chronicle, and the Church History, a storehouse of information collected by an indefatigable student, apologetic treatises, as the "," composed during the stress of persecution, commentaries and treatises on biblical geography, and numerous dogmatic writings, orations, and sermons.
He is called the Father of Church History.
New Catholic Dictionary