Library Eusebius of Caesarea Life of Constantine
Book 4
Chapter 75: He surpassed all Preceding Emperors in Devotion to God
Standing, as he did, alone and pre-eminent among the Roman emperors as a worshiper of God; alone as the bold proclaimer to all men of the doctrine of Christ; having alone rendered honor, as none before him had ever done, to his Church; having alone abolished utterly the error of polytheism, and discountenanced idolatry in every form: so, alone among them both during life and after death, was he accounted worthy of such honors as none can say have been attained to by any other; so that no one, whether Greek or Barbarian, nay, of the ancient Romans themselves, has ever been presented to us as worthy of comparison with him.
English translation by Ernest Cushing Richardson, in Nicene and Post-Nicene Fathers, Series II, Vol. I (eds. Philip Schaff and Henry Wace; Buffalo: Christian Literature Publishing Co., 1890). Public domain. Digital text via New Advent Church Fathers.