Eusebius of Caesarea, author of the Onomasticon
The name Eusebius is a common one. At least forty contemporaries are called by this name. Another famous church father is Eusebius of Nicomedia. St Jerome also occasionally used the name Eusebii. Therefore, the author of the Onomasticon is distinguished from the others by three epithets.
Because he was the bishop of Caesarea for a number of years, he is often called Eusebius of Caesarea. He himself chose and preferred the name Eusebius Pamphili after his teacher and friend, Pamphilius, the martyr.
No biography of Eusebius of Caesarea exists from contemporary times. It is believed that his successor Acacius, bishop of Caesarea, wrote one, but it is no longer extant. The place and the year of his birth are unknown. Earlier scholars suggested his birth was between 275 and 280. His parents were not Jewish, but again all proof that they were Christian is lacking. Arius called him "brother" to Eusebius of Nicomedia but this probably reflects Christian usage or theological kinship rather than blood relationship.
Little is known of his youth and early training. However, he soon became a student in the theological school of Caesarea founded by Origen. He studied under Pamphilius. Their relationship became more than that of student to teacher. They were friends and co-workers. Both were lovers of books and admirers of Origen. They probably added new books to the illustrious library gathered together at Caesarea by Origin during the last twenty years of his life. The theological, biblical, and exegetical tradition of Origen was most influential on Eusebius. Apparently about 296 when he still was in Palestine as a student, Eusebius had his first glimpse of Constantine.
The action of Eusebius during the great persecution is a matter of debate and much speculation. There is no doubt that during part of the time he was absent from Caesarea. He visited the imprisoned Pamphilius sometime during the period 307-310. There is a suggestion that he was arrested and held briefly himself in 309. He also reports that he witnessed the deaths of other martyrs in Tyre and elsewhere. After the death of Pamphilius in February 310, he fled to Egypt. It is suggested that he may have been arrested a second time (or for the first time). He was released when peace was restored in 313 and he returned to Caesarea. As noted above he was accused at the Council of Tyre in 335 of betraying the faith and of making the pagan sacrifice in order to survive. He did not suffer injury in the persecution it is true, but no evidence was produced in 335 or since to prove his supposed apostasy.
Shortly after 313 he became bishop of Caesarea. When he was ordained a deacon or priest is unknown. Some suggest he was not ordained at all until elected bishop. In 314 a brief persecution flared up under Licinius but it did not affect Palestine and Egypt. In 315 Eusebius is known as one who has been bishop for some time already. About 318 the Arian troubles began to come to a head. He was chairman of the Council of Nicea (the term president is deliberately avoided here) in 325. He and Constantine seem to have agreed on policy for the most part. As a moderate he felt the church could have room for both the followers of Arius and of Athanasius. He usually voted, however, with the majority. But after Nicea he spent much effort to prevent the complete alienation of the Arians from the mainstream of the Church.
There is no record of his stand on the Easter controversy. Eusebius if described some of the pomp of the Council in De Vita Constantini. He played a large role in all the proceedings and sat at Constantine’s right even though Rome, Alexandria and Antioch outranked Caesarea.
Eusebius was bishop of Caesarea for almost twenty-five years. In 330 he turned down the opportunity to become bishop of Antioch. He attended the Council of Antioch in 331 and the Council of Tyre in 335. Similarly, he was active in the Synods of Jerusalem and Constantinople in the same year. He was the chief orator for the 30th anniversary of Constantine’s reign. This panegyric was later attached to his Life of Constantine. Eusebius remained high in the regard of Constantine and was a close advisor to him at least from 325 on, if not as early as 313. Constantine died in 337 and Eusebius shortly after in 339 or 340 at about eighty years of age. His successor as bishop of Caesarea was present at the Synod of Antioch in 341.