The Ecclesiastical History of Sozomen

Such was the fate of Valens. The barbarians, flushed with victory, overran Thrace, and advanced to the gates of Constantinople. In this emergency, a few of the confederate Saracens sent by Mavia, together with many of the populace, were of great service. It is reported that Dominica, wife of Valens, furnished money out of the public treasury, and some of the people, after hastily arming themselves, attacked the barbarians, and drove them from the city.

Gratian, who at this period reigned conjointly with his brother over the whole Roman Empire, disapproved of the late persecution that had been carried on to check the diversity in religious creeds, and recalled all those who had been banished on account of their religion. He also enacted a law by which it was decreed that every individual should be freely permitted the exercise of his own religion, and should be allowed to hold assemblies, with the exception of the Manichæans and the followers of Photinus and Eunomius.