The barbarians also, who through all these ages were growing stronger while Rome grew weaker, became ever a more serious menace. The internal disorder of the Empire left its frontiers often unguarded. The Germans plundered Gaul in the West, the Persians ravaged Asia in the East. In fact, so comparatively strong had the Persians grown that one emperor, venturing against them, was defeated and captured, and lived out his miserable life a Persian slave. Rome could not rescue him.[12] In the year 284 there came to the front an emperor "of iron," Diocletian. He did what Augustus had done three centuries before, re-formed and recast the government of the world. The last empty ceremonies of the Republic were discarded. Even the pretence of Rome's leadership was brushed aside. The Empire was divided into four districts, each with a capital of its own, and Diocletian selected three other generals to share its rule with him. He and his colleagues restored the long-lost peace. They chastised the barbarians. Diocletian's reforms saved the Roman fabric from what seemed inevitable extinction, and enabled it to exist in some shape for almost another two hundred years. His system of division did not, however, save the Empire from civil wars. No sooner was his restraining hand removed than his colleagues fought among themselves, until Constantine overthrew his antagonists and once more united the entire Empire. Constantine became a Christian.[13] It has been repeatedly asserted that his conversion was one of policy rather than belief; and there could be no stronger evidence of the changed position of the new faith. Diocletian had ordered a persecution against it, the last and most terrible which its martyrs suffered. But all that was best and most energetic and most living in the moribund Empire seemed to have gathered round the Church. The persecution did but emphasize its worth and influence. Constantine did not force his followers to change their beliefs with him; but he encouraged and rewarded those who did. Under him was held the first general council of the faith. The bishops gathered from all the different cities of the world to compare ideas and settle more exactly the doctrines to be taught. Christianity stepped out from its hiding-place and supplanted paganism as the state religion of the Empire.[14]