u8 THE ROMAN DOMINION who appear to have been closely akin to the Danes and Norse- men of a later period. But it was not only the Teutonic hordes that were surging against the barriers of the empire ; in the far east the Persians, long subject to the Parthians, had succeeded in flinging off the yoke and setting up a new empire under the dynasty called the Sassanidae. The empire had need to choose soldiers for its emperors. Decius was the first who actually fell in the field. Valerian was made captive and slain by the Persian monarch. Another Emperor Claudius inflicted a great rout on the Goths. He was succeeded by another stout soldier, Aurelian, by birth an Illyrian peasant. He also checked the Goths, and after a brief interval was succeeded by another soldier, Probus, also an Illyrian, who fought successfully against Goths and Persians. And then among the many dim names belonging to this period, in which a reign of more than two or three years was an exception, emerges that of Diocletian, a Dalmatian soldier who had risen from the Diocletian, ranks by sheer force of character and ability. The A.D. 284. time had come when a great change in the Imperial system had become necessary ; it was the work of Diocletian to reorganise the empire. Three centuries had passed since the first establishment of the Roman Empire by Augustus on the foundations laid by Julius survey from Caesar, twenty-seven years before the Christian era Augustus to began. The period can be conveniently divided Dioc e lan. ^ Q tnree sec ti ns of almost equal length, each of which has certain special characteristics. The Julian emperors ruled from B.C. 27 to a.d. 69. The Imperial system was established in the first half of this time by the ability of Augustus and Tiberius so firmly that it survived the follies, vices and crimes of the emperors during the second half, including therein the last years of Tiberius. From 70 a.d. to 180, the whole series, with the one exception of Domitian, were rulers to whom the Roman world owed a debt of gratitude ; they rank among the ablest princes in history. Probably the administra- tion throughout the empire was consistently better than at any other time. The third period dates from the accession of Corn- modus in 180 a.d. to the accession of Diocletian in 284.
