Nicene and Post-Nicene Fathers, Ser. II, Vol I:
The Life of Constantine with Orations of Constantine and Eusebius.: Chapter XXIV

p. 546 Chapter XXIV.—That he described himself to be a Bishop, in Charge of Affairs External to the Church.

Hence it was not without reason that once, on the occasion of his entertaining a company of bishops, he let fall the expression, “that he himself too was a bishop,” addressing them in my hearing in the following words: “You are bishops whose jurisdiction is within the Church: I also am a bishop, ordained by God to overlook whatever is external to the Church.” 3324 And truly his measures corresponded with his words: for he watched over his subjects with an episcopal care, and exhorted them as far as in him lay to follow a godly life.

Footnotes

This saying of Constantine has occasioned a deal of exegesis and conjecture. Compare monograph of Walch mentioned under Literature in the Prolegomena for discussion and references to other older literature.