No auguries—which were taken by observing the flight of birds, as omens were by noting their voices. These observances of course disappeared from the Roman army as soon as the empire became Christian. In saying that the Name of the Saviour leads the troops to war, St. Ambrose probably alludes to the Labarum or banner emblazoned with the monogram Χρ, which is composed of the two first letters of the Name Χριστός.