Res Gestae

In those same days Valens was troubled for two reasons: first, by the news that the Lentienses had been defeated; secondly, because Sebastianus wrote from time to time exaggerating his exploits. He therefore marched forth from Melanthias, being eager to do some glorious deed to equal his young nephew, whose valiant exploits consumed him with envy.[*](Eunapius says that Gratian had also, at the wish of his army, taken the younger Valentinian as his colleague, without consulting his uncle Valens; moreover, that Valens was an Arian, while Gratian, according to Ambrose, was a Christian (christianissimus). [Val. in Wagner-Erfurdt.]) He had under his command a force made up of varying elements, but one neither contemptible, nor unwarlike; for he had joined with them also a large number of veterans, among whom were other officers of high rank and Trajanus, shortly before a commander-in-chief, whom he had recalled to active service.

And since it was learned from careful reconnoitring that the enemy were planning with strong guards to block the roads over which the necessary supplies were being brought, he tried competently to frustrate this attempt by quickly sending an infantry troop of bowmen and a squadron of cavalry, in order to secure the advantages of the narrow passes, which were near by.