Eusebius, of Caesarea, Bishop of Caesarea, approximately 260-approximately 340. Historia ecclesiastica

The Ecclesiastical History (Ancient Greek: Ἐκκλησιαστικὴ Ἱστορία, Ekklēsiastikḕ Historía; Latin: Historia Ecclesiastica), also known as The History of the Church and The Church History, is a 4th-century chronological account of the development of Early Christianity from the 1st century to the 4th century, composed by Eusebius, the bishop of Caesarea. It was written in Koine Greek and survives also in Latin, Syriac, and Armenian manuscripts.