DIOCLETIAN.--Once more the gigantic and weakened frame of the Roman Empire was invigorated by a change in the character of the chief rulers and in the method of government. _Diocletian_ (284-305), one of a number of energetic emperors who were of Illyrian birth, first stripped the imperial office of its limitations, and converted it into an absolute monarchy. This new system was carried to its completion by _Constantine_. _Diocletian_ took from the Senate what political jurisdiction was left to it. He abolished the difference between the treasury of the state and the private coffers of the prince. The precedence of Rome was taken away by making other great cities to be seats of government. There were to be two emperors under the title of _Augustus_, with two _Caesars_ under them; and thus the empire was divided, for administrative purposes, into four parts. _Maximian_, the second Augustus, was to rule over Italy, Africa, and the islands, with _Milan_ for his residence. _Constantius Chlorus_ had the western provinces, --Spain, Gaul, and Britain. At _Nicomedia_, _Diocletian_, a man of imposing presence and of great talents as a statesman, exercised rule for twenty years with efficiency and success. The new system, if it involved the peril of strife among the regents, led to a more vigilant and efficient government in the different provinces, and provided for a peaceful succession to the throne. But the government came to resemble, in the omnipotence of the emperor, in the obsequious homage paid to him, and in the cringing manners of the court, an Oriental despotism. The old heathen religion was considered by conservative Romans to be an essential part of the imperial system, and indispensable to the unity of the empire. It was this view, in connection with other influences, which moved _Diocletian_, near the close of his reign, in 303, to set on foot a systematic persecution of the Christian Church, by a series of extremely severe and well-contrived measures, through which it was designed to extirpate the new religion. The last great persecution, in the reign of _Decius_, cruel though it had been, did not approach in severity this final effort to exterminate the disciples of the Christian faith, who had now become very numerous. Terrible sufferings were inflicted, but without avail. In 305 Diocletian, partly on account of a serious illness, formally abdicated, and obliged _Maximian_ to do the same. Civil wars followed, until _Constantine_, the son of _Constantius_, gained the supremacy, first as joint ruler with _Licinius_, who governed in the East, and then, after a bloody struggle which began in A.D. 314, as sole master of the empire (A.D. 323).