The Ecclesiastical History of Sozomen

When he had completed his preparations for war, Theodosius declared his younger son Honorius emperor, and leaving him to reign at Constantinople conjointly with Arcadius, who had previously been appointed emperor, he departed from the East to the West at the head of his troops. His army consisted not only of Roman soldiers, but of bands of barbarians from the banks of the Ister. It is said that when he left Constantinople, he came to the seventh milestone, and went to pray to God in the church which he had erected in honor of John the Baptist; and in his name prayed that success might attend the Roman arms, and besought the Baptist himself to aid him. After offering up these prayers he proceeded towards Italy, crossed the Alps, and took the first guard-posts. On descending from the heights of these mountains, he perceived a plain before him covered with infantry and cavalry, and became at the same time aware that some of the enemy’s troops were lying in ambush behind him, among the recesses of the mountains. The advance guard of his army attacked the infantry stationed in the plain, and a desperate and very doubtful conflict ensued. Further, when the army surrounded him, he considered that he had come into the power of men, and could not be saved even by those who would desire to do so, since those who had been posted in his rear were seizing the heights; he fell prone upon the earth, and prayed with tears, and God instantly answered him; for the officers of the troops stationed in ambush on the height sent to offer him their services as his allies, provided that he would assign them honorable posts in his army. As he had neither paper nor ink within reach, he took up some tablets, and wrote on them the high and befitting appointments he would confer upon them, provided that they would fulfill their promise to him. Under these conditions they advanced to the emperor. The issue did not yet incline to either side, but the battle was still evenly balanced in the plain, when a tremendous wind descended into the face of the enemy. It was such an one as we have never before recorded, and broke up the ranks of the enemies. The arrows and darts which were sent against the Romans, as if projected by the opposing ranks, were turned upon the bodies of those who had cast them; and their shields were wrenched from their hands, and whirled against them with filth and dust. Standing thus exposed, in a defenseless condition, to the weapons of the Romans, many of them perished, while the few who attempted to effect an escape were soon captured. Eugenius threw himself at the feet of the emperor, and implored him to spare his life; but while in the act of offering up these entreaties, a soldier struck off his head. Arbogastes fled after the battle, and fell by his own hands. It is said that while the battle was being fought, a demoniac presented himself in the temple of God which is in the Hebdomos, where the emperor had engaged in prayer on starting out, and insulted John the Baptist, taunting him with having his head cut off, and shouted the following words: “You conquer me, and lay snares for my army.” The persons who happened to be on the spot, and who were waiting impatiently to learn some news of the war, were amazed, and wrote an account of it on the day that it occurred, and afterwards ascertained that it was the same day as that on which the battle had been fought. Such is the history of these transactions.