Roman emperor, A. D. 337-361, whose name is sometimes written Flavius Claudius Constantius, Flavius Valerius Constantius, and Constantinus Constantius. He was the third son of Constantine the Great, and the second whom he had by his second wife, Fausta; he was born at Sirmium in Pannonia on the 6th of August, A. D. 317, in the consulate of Ovidius Gallicanus and Septimius Bassus. He was educated with and received the same careful education as his brothers, Constantine and Con stans, was less proficient in learned pursuits and fine arts, but surpassed them in gymnastic and military exercises. He was created consul in 326, or perhaps as early as 324, and was employed by his father in the administration of the eastern provinces. At the death of his father in 337, Constantius was in Asia, and immediately hastened to Constantinople, where the garrison had already declared that none should reign but the sons of Constantine, excluding thus the nephews of the late emperor, Dalmatius and Hannibalianus, from the government of those provinces which had been assigned to them by Constantine, who had placed Dalmatius over Greece, Macedonia, Thrace,
After this the three sons of Constantine the Great had an interview at Sirmium in Pannonia, and made a new division of the empire (September, 337), in which Constantine, the eldest, received Gaul, Spain, Britain, and part of Africa ; Constantius, the second and the subject of this article, Thrace, Macedonia, Greece, the Asiatic provinces, and Egypt; and Constans, the youngest, Italy, Illyricum, and the rest of Africa. The ancient world was thus governed by three youths of twenty-one, twenty, and seventeen years of age. Immediately after the death of Constantine the Great a war broke out with the Persian king, Sapor II., which was chiefly carried on in Mesopotamia and on the frontiers of Syria, and, with short interruptions, lasted during the whole reign of C(onstantius. This war was to the disadvantage of the Romans (Greeks), who were vanquished in many battles, especially at Singara, in 343, where Constantius commanded in person, and after having carried the day, was routed with great slaughter of his troops in the succeeding night. On the other hand, the Persians sustained great losses in their fruitless attempts to take the strong fortress of Nisibis, the key of Mesopotamia; and as other fortified places in that country as well as in the mountains of Armenia were equally well defended, Sapor gained victories without making any acquisitions.
Being thus engaged in the east, Constantius was prevented from paying due intention to the west, and he was obliged to be a quiet spectator of the civil war between his brothers, in which Constantine was slain at Aquileia, and Constans got possession of the whole share of Constantine in the division of the empire (A. D. 340). In 350, Constans was murdered by the troops of Magnentius, who assumed the purple and was obeyed as emperor in Britain, Gaul, and Spain; at the same time Vetranio, commander of the legions in the extensive province of Illyricum, was forced by his troops to imitate the example of Magnentius, and he likewise assumed the purple. It was now time for Constantius to prove with his sword that none but a son of the great Constantine should rule over Rome. At the head of his army he marched from the Persian frontier to the West. At Heracleia in Thrace ambassadors of Magnentius waited upon him, proposing that he should acknowledge their master as emperor, and cement their alliance by a marriage of Constantius with the daughter of Magnentius, and of Magnentius with Constantina, eldest sister of Constantius; they threatened him with the consequences of a war should he decline those propositions. Constantius dismissed the ambassadors with a haughty refusal, and, sending one of them back to Magnentius, ordered the others to be put in prison as the agents of a rebel. His conduct towards Vetranio tended to a reconciliation; but while he promised to acknowledge him as co-emperor if he would join him against Magnentius, he secretly planned treachery. Having bribed or persuaded the principal officers of Vetranio to forsake their master if it should suit his plans, he advanced towards Sardica, now Sophia, where he met with Vetranio, both of them being at the head of an army, that of Vetranio, however, being by far the stronger. Had Vetranio, a straightforward veteran, who could disobey but was not made for more refined perfidy, now acted in the spirit of Constantius, he could have seized his rival in the midst of his camp; but the result was very different. On a plain near Sardica a tribune was erected, where the two emperors showed themselves to their troops, who filled the plain apparently for the purpose of being witnesses of a ceremony by which the empire was to have two lawful heads. Constantius first addressed the armed crowd, and artfully turning upon his " legitimate" opinion, that a son of the great Constantine was alone worthy to reign, suddenly met with a thunder of applause from his own troops as well as those of Vetranio, who, either spontaneously or in accordance with the instructions of their officers, declared that they would obey no emperor but Constantius. Vetranio at once perceived his situation : he took off his diadem, knelt down before Constantius, and acknowledged him as his master, himself as his guilty subject. Constantius evinced equal wisdom: he raised Vetranio from the ground, embraced him, and, as he despised a throne, assigned him a pension, and allowed him to spend the rest of his days at Prusa. (A. D. 351.)
Constantius now turned his arms against Magnentius, after having appointed his cousin Gallus as Caesar and commander-in-chief of the army against the Persians. At Mursa, now Essek, a town on the river Drave in Hungary, Magnentius was routed (28th of September, A. D. 351) in a bloody battle, in which Constantius evinced more piety than courage; but where the flower of both armies perished. The conquest of Illyricum and Italy was the fruit of that victory, and Magnentius fled into Gaul. There he was attacked in the east by the army under Constantius, and in the west by another army, which, after having conquered Africa and Spain, crossed the Pyrenees and penetrated into Gaul. After another complete defeat at mount Seleucus in the Cossian Alps, and the rebellion of the principal cities in Gaul, Magnentius, reduced to extremity, put an end to his life, and his brother Decentius followed his example. (A. D. 353.) [MAGNENTIUS.] Constantius became thus master of the whole West. He avenged the murder of his brother Constans, and established his authority by cruel measures, and neither the guilty nor the innocent were exempt from his resentment.
Once more the immense extent of the Roman
In 357, Constantius visited Rome, where he celebrated an undeserved triumph. Imitating the example of Augustus, he ordered the great obelisk which stood before the temple of the Sun at Heliopolis to be carried to Rome, where it was erected in the Circus Maximus. (Having been thrown down, it was placed by order of pope Sixtus V. before the portal of the church of St. John Lateran, and is known as the Lateran obelisk.) From Rome Constantius went to Illyricum, where his generals made a successful campaign against the Quadi and Sarmatians, and thence returned in 359 to Asia to meet the armies of Sapor, who had once more invaded Mesopotamia, and taken Amida, now Diyárbekr, and the minor fortresses of Singara and Bezabde. Before Sapor appeared in the field, Gaul was invaded by the Alemanni and the Franks, but their power was broken in a three years' campaign by Julian, who made Chnodomarius, the king of the Alemanni prisoner [CHNODOMARIUS]; and not only by his martial deeds, but also by his excellent administration, which won him the hearts of the inhabitants, he excited the jealousy of Constantius. Accordingly, orders arrived in Gaul that the legions employed there should march to the defence of the East. The pretext for this command was, that Gaul being tranquil, no great army was required there, but the real motive was the fear that Julian might abuse his popularity, and assume the purple. Instead of preventing tnat event, the iniprudent order caused it. The troops refused to march; and Julian having nevertheless brought thicu into motion, they suddenly proclaimed him emperor. (A. D. 360.) It is related in the life of Julian how he acted under these circumstances; his protestations of innocence were misconstrued; his ambassadors, who met with Constantius at Caesareia, were dismissed with anger, and war was declared. Constantius, with the greater part of his army, marched to the West, and the empire was on the eve of being shaken by a dreadful civil war, when the sudden death of Constantius at Mopsocrene, near Tarsus in Cilicia (3rd of November, A. D. 361), prevented that calamity, and made Julian the sole master of the empire [JULIANUS.] By his third wife, Maxima Faustina, Constantius left one daughter, who was afterwards married to the emperor Gratian. (Amm. Marc. lib. xiv.--xxi.; Zosimus, lib. ii. iii.; Agathias, lib. iv.; Euseb. Vita Constantin. lib. iv.; Eutrop. lib. 10.5, &c.; Julian. Orat. i. ii.; Liban. Orat. iii.-x.; Zonar. lib. xiii.; the authorities referred to under Constantinus 1l. and Constans I.; Tillemont, Histoire des Empereurs.)
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