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

Chapter VI.—That he was the Servant of God, and the Conqueror of Nations.

Thus, like a faithful and good servant, did he act and testify, openly declaring and confessing himself the obedient minister of the supreme King. And God forthwith rewarded him, by making him ruler and sovereign, and victorious to such a degree that he alone of all rulers pursued a continual course of conquest, unsubdued and invincible, and through his trophies a greater ruler than tradition records ever to have been before. So dear was he to God, and so blessed; so pious and so fortunate in all that he undertook, that with the greatest facility he obtained the authority over more nations than any who had preceded him, 3064 and yet retained his power, undisturbed, to the very close of his life.

Footnotes

Compare the various wars against Franks, Bructerians, Goths, Sarmatians and others mentioned in Life in Prolegomena. Compare also chapter 8 of this book.