In dealing with the established institutions of Rome, where Constantine had already charted the pragmatic course which would be followed by his Christian successors through the century, the emperor faced constraints against the thoroughgoing eradication of paganism which the will of God ideally required - and of which Constans and his brother were eloquently reminded about this time in Firmicus Maternus' pamphlet On the Error of Profane Religions. A more definitive legacy of Constantine's was the transformation of ecclesiastical politics into affairs of state. Constans' destroyer, Fl. Magnus Magnentius, was representative of a new breed of capaces imperii springing up in the western provinces in the fourth century. In over twenty years of defending Roman territory in the east, Amida was the first place to fall to the Persians. At Constantinople he ordered an investigation into the disaster, which resulted in Ursicinus' being retired from his command.