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

Chapter VII.—That Victory everywhere followed the Presence of the Standard of the Cross in Battle.

Indeed, wherever this appeared, the enemy soon fled before his victorious troops. And the emperor perceiving this, whenever he saw any part of his forces hard pressed, gave orders that the salutary trophy should be moved in that direction, like some triumphant charm 3168 against disasters: at which the combatants were divinely inspired, as it were, with fresh strength and courage, and immediate victory was the result.

Footnotes

Or “remedy” i.e. that which keeps off harm.