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

Chapter XX.—The Form of Prayer given by Constantine to his Soldiers.

“We acknowledge thee the only God: we own thee, as our King and implore thy succor. By thy favor have we gotten the victory: through thee are we mightier than our enemies. We render thanks for thy past benefits, and trust thee for future blessings. Together we pray to thee, and beseech thee long to preserve to us, safe and triumphant, our emperor Constantine and his pious sons.” Such was the duty to be performed on Sunday by his troops, and such the prayer they were instructed to offer up to God.