Caligula, Nero, Commodus, Caracalla, and Heliogabalus, may pass unnoticed, as may also the military achievements of some of the later emperors. The reign of Diocletian, however (A. D. 248-305), constitutes an epoch in the history of the Empire. Finding the unwieldy mass too great for the administration of a single individual, he divided it between himself and his colleague Maximian, assigning to Maximian the western or Latin-speaking nations, and retaining the East in his own hands. Under each emperor there was to be a royal personage called Cæsar, who was to govern part of that emperor's section of the Empire, and afterwards succeed him in the chief dignity. This arrangement did not last long; and after various subdivisions of the Empire, and struggles between emperors and Cæsars, the whole was reunited under Constantine the Great (A. D. 306-337). Under this remarkable man Christianity was established as the religion of the Empire.
During the three centuries which had elapsed between the crucifixion of Christ—which took place in the nineteenth year of the reign of Tiberius—and the accession of Constantine to the supreme government of the whole Empire, the new religion had been silently but surely spreading itself; first among the Jews, then among the Greek or eastern, and lastly among the Latin or western Gentiles. It had been subjected to numerous persecutions, some local, and others general, over the whole Empire; but had, nevertheless, made such progress, that it is calculated that in Constantine's reign about a twentieth part of the whole population of the Empire were professed Christians, while even over the nineteen-twentieths who continued in polytheism, the indirect influence of Christianity had been immense. Led to embrace Christianity himself, although with a considerable tincture of polytheistic superstition, Constantine gave his imperial recognition to the already fully-organized ecclesiastical system of the Christians, with its churches, presbyters, bishops, metropolitans. The civil ban having thus been removed from the profession of Christianity, it began to prevail in form, as it already did in fact, over the heterogeneous polytheism of the Empire.
Another important act of Constantine's reign, besides his proclamation of toleration for Christianity (A. D. 321), was his removal of the seat of empire from Rome to Constantinople. Not long after this was effected, Constantine died at the age of sixty, leaving the Empire divided among his three sons. One of them, Constantius, ultimately acquired the whole, and transmitted it to his successors; but in the year 395, Theodosius, one of these successors, effected a permanent separation between the East and the West. From that date, the history of Rome divides itself into two distinct histories—that of the Western or Latin and that of the Eastern or Greek empire. The latter protracted its existence till A. D. 1453, when Constantinople was taken by the Turks: the former crumbled to pieces much earlier, before the attacks of the northern barbarians, who finally destroyed it in 476.
DOWNFALL OF THE WESTERN EMPIRE.
From an early period, the Empire had been assailed on its northern frontier by the German and Sclavonian races living east of the Rhine and north of the Danube. Partly by force, and partly by negotiation, the au-
