The reign of Jovian lasted so short a time, June, 363, to February, 364, that he had no time to develop a policy, and the assertion of Theodoret that he extinguished the heathen sacrificial fires is doubtful. On the death of Jovian, Valentinian was elected Emperor, who soon associated with himself his brother Valens as his colleague for the East. The two were tolerant toward heathenism, but Valens took an active part in favor of Arianism, while Valentinian held aloof from doctrinal controversy. On the death of Valentinian I, his sons Gratian (murdered at Lyons, 383) and Valentinian II (murdered at Vienne by Arbogast, 392), succeeded to the Empire. Under them the policy of toleration ceased, heathenism was proscribed. In the East under Theodosius, appointed colleague of Gratian in 379, the same policy was enforced. Arianism was now put down with a strong hand in both parts of the Empire. (_a_) Ammianus Marcellinus, _Roman History_, XXX, 9, § 5. The religious policy of Valentinian I. Ammianus Marcellinus is probably the best of the later Roman historians, and is the chief authority for much of the secular history from 353 to 378, in which period he is a source of the first rank, writing from personal observation and first-hand information. Ammianus was himself a heathen, but he seems not to have been embittered by the persecution to which his faith had been subjected. He was a man of a calm and judicial mind, and his judgment is rarely biassed, even when he touches upon ecclesiastical matters which, however, he rarely does. Valentinian was especially remarkable during his reign for his moderation in this particular—that he kept a middle course between the different sects of religion, and never troubled any one, nor issued any orders in favor of one kind of worship rather than another; nor did he promulgate any threatening edicts to bow down the necks of his subjects to the form of worship to which he himself was inclined; but he left these parties just as he found them, without making any alterations. (_b_) _Codex Theodosianus_, XII, 1, 75; A. D. 371. In this edict Valentinian I confirms the immunities of the heathen priesthood which had been restored by Julian. The heathen priesthood is here shown to continue as still open to aspirants after political honors and conferring immunities upon those who attained it. The curial had to pass through the various offices in fixed order before he attained release from burdens which had been laid upon him by the State’s system of taxation.