Professor Alfoldi describes the conflict in the reign of Emperer Valentinian I between the old world of pagan thought and custom and the new order created by the conversion to Christianity of Constantine the Great. Despite Valentinian's noble policy of tolerance, he regarded the practice of magic by leading Roman nobles, which the Senate and aristocracy of Rome considered acceptable maintenance of traditional rites, as disloyalty and dangerous to his person and to the state. In Valentinian's reign the struggle was manifested in the trials of practitioners of magic.