Having subdued the Persians, Constantino now turned his arms against the usurpers of his power; among whom were Veteranio, a general of infantry in Romania, and Nepotianus the son of Eutropia, the sister of Constantine the Great. Nepotianus made himself master of Rome, and committed great slaugh ter among the inhabitants; but Marcellinus, the prime minister of Magnentius, marched against him, and after a bloody battle, defeated and slew Nepotianus. Marcellinus and Magnentius committed great cruelties on the inhabitants; and by means of the heavy exac tions which they made upon the rich, they were enabled to assemble a powerful army, composed of the various nations that were subjugated by Rome. Before, how ever, trying the chances of war, Magnentius, along with the other usurper Veteranio, proposed terms of peace to the emperor. Constantius was induced to make a separate treaty with Veteranio, and to assume him as a partner in the empire; but when Veteranio ascended the tribunal along with Constantino, the soldiers pulled him down and refused to acknowledge any other em peror than Constantius.
After raising his cousin Gallus to the rank of Caesar, Constantly's excited the Franks to invade Gaul; but Magnentius marched into Pannonia to meet him, and having challenged him to fight on the plains of Sciscia, upon the Save, Constantius's army fell into an ambus cade, and were routed with great slaughter. Elated with this success, Magnentius haughtily rejected offers of peace made to him by Constantius, and a general engagement having been brought on at Mum, Magnentius was defeated with the loss of 21,000 men.
After various other successes, in which took Aquileia,—Africa, Italy, and Spain declared for Constantino; and Magnentius, perceiving the desper ate condition of his affairs, despatched an assassin to murder Gallus Cesar, in the hopes of compelling the emperor to withdraw his forces from Gaul. The as sassin, however, was seized and executed, and Mag nentius, having experienced a severe reverse in Gaul, took refuge in Lyons, where he slew himself and all his relations who accompanied him, from the dread of being delivered up by his soldiers to the emperor.— His brother, Decentius, whom he had made his partner in power, also strangled himself, and Constantius re mained the sole possessor of the empire.
The general tranquillity, however, was soon dis turbed by the irruptions of the barbarians into many of the provinces; but especially by the tyrannical con duct and cruelties of Gallus, who, at the instigation of his wife Constantine, filled the provinces with blood. As soon as Constantino heard of his exactions and his cruelties, he sent for him to Italy; but having made a fruitless attempt to revolt, he confessed his crime, and was put to death by the order of the emperor.
After quelling an insurrection in Germany, and put ting to death Sylvanus, a leader of the Franks who had revolted, Constantius was called upon to defend Gaul against the inroads of the barbarians. Deeming
it imprudent to leave Italy, he raised his cousin Julian to the dignity of Caesar; and though this young man had devoted himself principally to literature, he yet exhibited the greatest bravery and skill in the field. Constantius appointed him governor of Gaul, and gave him his sister Helena in marriage. He therefore set out for Gaul, and having come up with the barbarians in the thick woods between Auxerre and Troyes, he defeated them with great slaughter. Having next de feated the Germans, he advanced to Cologne, and after repairing its fortifications, he took up his winter quar ters at Sens. Here he was besieged by the barbarians for nearly a month, and having at last forced them to retire, he was appointed by Constantius commander in chief of all the forces in Gaul. After defeating the Leti with great slaughter, and forcing the barbarians to quit the islands of the Rhine, he came up with their main army, commanded by Chnodomarius and six other kings, who had encamped in the neighbourhood of Strasburg, and having given them battle he defeated them with immense loss, and sent Chnodomarius a prisoner to Rouse. Julian next entered Germany, and concluded a truce with the barbarians, which was af terwards converted into a peace favourable to Rome.
After a successful expedition against the German tribes, Constantius declared war upon Sapor, king of Persia, and marched against him in person: but having requested a portion of Julian's troops to assist him, the soldiers refused to quit their favourite general, and went so far as to proclaim him emperor. Julian seems to have had no farther ambition than to share the so vereignty with his cousin; lint Constantino refused to divide his power; and, as he was marching against his rival, he was seized with a fever at Mosucrene, at the foot of Mount Taurus, which cut him off in the 45th year of his age.
The reign of Constantius has been rendered remark able in history, by the peculiarity of some of the laws which he enacted. In the year 356, he made it a ca pital crime to offer sacrifices, or to pay any sort of worship to idols. In 357, he enacted that the effects of every Christian who renounced his religion for Judaism, should be confiscated; and he removed every kind of impost from such of the travelling merchants as were ecclesiastics. In 358, he declared all magi cians, augurs, astrologers, and pretenders to divina tion, enemies to mankind; and in 359, he established a court of inquisition against all who consulted heathen oracles. But this tribunal was characterized by the same barbarities which disgraced a similar establish ment in succeeding ages.