Eusebius’s Ecclesiastical History (folio pages 1–8, 27–32, 273, 326), Constantine’s Oration (pages 86, 92), the Proem of Eusebius, Successions of the Holy Apostles:

Together with the time from our Savior unto us (hitherto continued) I determined to publish: will I take from the dispensation and divinity of our savior Christ—higher and deeper to be considered than that which concerns his humanity, diviner than it seemeth to many termed Christians (page 2).  

His generation who can declare: the Word was with God, and God was the Word. The prophets also, which conceived of God with the cleansed eyes of the mind, have known him. The Son of God—the Word—appeared to the Father before any books were written (pages 3, 6, 7, and so after).