Diocletian, on assuming the imperial power, found the Empire assailed by enemies in various quarters--on the Persian frontiers, on the side of Germany and of Illyricum, and in Britain; besides which a serious revolt had broken out in Gaul among the rural population, under two leaders who had assumed the title of emperor. To quell the disturbance in Gaul, Diocletian sent his old friend Maximianus, a native of Pannonia, and a brave but rude uncultivated soldier. Maximianus defeated the Bagaudi, for such was the name the rustic insurgents had assumed. In the year 286, Diocletian chose Maximianus as his colleague in the Empire, under the name of Marcus Valerius Maximianus Augustus, and it is to the credit of both that the latter continued ever after faithful to Diocletian and willing to follow his advice. Maximianus was stationed in Gaul and on the German frontier to repel invasion; Diocletian resided chiefly in the East to watch the Persians, though he appears to have visited Rome in the early part of his reign. About 287 the revolt of Carausius took place. In the following year Maximianus defeated the Germans near Treviri, and Diocletian himself marched against other tribes on the Rhaetian frontier; the year after he defeated the Sarmatians on the lower Danube. In the same year, 289, peace was made between Carausius and the two emperors, Carausius being allowed to retain possession of Britain. In 290 Maximianus and Diocletian met at Milan to confer together on the state of the Empire, after which Diocletian returned to Nicomedia. The Persians soon after again invaded Mesopotamia and threatened Syria; the Quinquegentiani, a federation of tribes in the Mauritania Caesariensis, revolted; another revolt under one Achillaeus broke out in Egypt; another in Italy under a certain Julianus. Diocletian thought it necessary to increase the number of his colleagues in order to face the attacks in the various quarters. On the 1st of March, 292, or 291, according to some chronologists, he appointed Galerius as Caesar, and presented him to the troops at Nicomedia. At the same time Maximianus adopted on his part Constantius called Chlorus. The two Caesars repudiated their respective wives; Galerius married Valeria, Diocletian's daughter, adding to his name that of Valerianus; and Constantius married Theodora, daughter of Maximianus. Galerius was a native of Dacia, and a good soldier, but violent and cruel; he had been a herdsman in his youth, for which he has been styled, in derision, Armentarius. The two Caesars remained subordinate to the two Augusti, though each of the four was entrusted with the administration of a part of the Empire. Diocletian kept to himself Asia and Egypt; Maximianus had Italy and Africa; Galerius, Thrace and Illyricum; and Constantius had Gaul and Spain. But it was rather an administrative than a political division. At the head of the edicts of each prince were put the names of all the four, beginning with that of Diocletian.