VALENTINIAN III., emperor of the West from 425 to 455, the son of Constantius and Placidia, daughter of the great Theodosius, was declared Caesar at Thessalonica under the auspices of Theodosius II., and again the following year at Rome, in the seventh year of his age. His reign of thirty years was a period of great and terrible events associated with the names of Attila, Genseric, and Aetius, the “last of the Romans.” This period is marked by the dismemberment of the Western empire, the conquest of the province of Africa by the Vandals in 439, the final abandonment of Britain in 446, the loss of great portions of Spain and Gaul, in which the barbarians had established themselves, and the ravaging of Sicily and of the western coasts of the Mediterranean by the fleets of Genseric. As a set-off against these calamities there was the great victory of Aetius over Attila in 451 in the neighbourhood of Châlons. (See Rome, vol. xx. p. 781.) The burden of taxation became more and more intolerable as the power of Rome decreased, although there were a partial remission of taxes in 450 and a cancelling of arrears in consequence of the general impoverishment of Rome’s subjects. Ravenna was Valentinian’s usual residence; but he fled to Rome in 452 on the approach of Attila, who, after ravaging the north of Italy, died in the following year. In 454 Aetius, between whose son and a daughter of the emperor a marriage had been arranged, was treacherously murdered by Valentinian. Next year, however, the crime was avenged by the assassination of the emperor as he was looking on at some games in the Campus Martius. He was a contemptible creature, cowardly, self-indulgent, without spirit, and without ability. With Valentinian III. the family of Theodosius became extinct....