The council of Saragossa in 380 censured excessive ascetism associated with Priscillian and his followers but did not directly condemn them. Shortly after the council, Priscillian became even the bishop. Therefore, Bishop Hydatius of Merida, their main adversary, appealed to the emperor Gratian and received from him the rescript "against the false bishops and Manichaeans", directed against Priscillian. Priscillian, for his part, went to Italy to look for support in Milan, and when he found none, he went to Rome. For this occasion, he composed the formal petition (libellus) in order to prove his orthodoxy. For a detailed analysis of the Liber ad Damasum see (van Waarden 2014).