Valentinian I continued Julian’s work with an iron hand and will. During this interlude of more than a century in the migration of the tribes the victory of Christendom was effected in Rome, and also its entry amongst the Germanic peoples in the form of Arianism, The Germans received a fresh impetus by the incursions of the Huns, which extended from the Crimean wall to the Loire. The western Goths, who were already in a state of transition from barbarism to civilisation, fled before these Mongols to the Romans. Tricked by imperial officers, wronged and deceived, they seized upon the sword; the decisive battle at Hadrianopolis, in which the emperor Valens fell, made them lords of the European provinces of the Eastern Empire. The joint empire was once more saved by Theodosius, the last of the great emperors, who contrived to appease the Goths. But when in 395 the last and permanent division of the empire took place under Arcadius and Honorius, the two weak sons of Theodosius, who were still in their boyhood, the danger to western Rome flared up again, even more terrible than before.
For nearly eight hundred years the capital of the world had seen no conqueror within its walls. Alaric the Visigoth, a fearless warrior, became after the emperor had caused his best commander Stilicho to be put to death the first successor of the Gallic Brennus.
But the twofold occupation of Rome by Alaric was of no more importance as an epoch in the barbarian invasion than was the later occupation by Genseric in the year 455. Alaric did not wish to destroy the empire, only to rule over his people in and with it; the Vandal wished for nothing but plunder. From the passage of the Rhine by the Vandals and Suevi, at the beginning of the year 406, to the incursion of the Visigoths into Gaul in 412, was a far more important period in the barbaric advance. In the year 409 the first went across the Pyrenees, and in 411 permanently established themselves in Spain. In the year 413 the Burgundiones took possession of the country now bearing their name; in the year 419 southwestern Gaul was at last formally ceded to the Visigoths by the emperor Honorius. This people acknowledged a certain, though only nominal, supremacy on the part of Rome. Rome, through its last great commander Aëtius, brought into subjection the whole of the rest of Gaul and the greater part of Spain. Far worse, however, was the loss it suffered at the hands of the most terrible of all the Germanic conquerors, Genseric the king of the Vandals; who in the year 427 deprived it of the distant and rich Africa, its granary, as well as of the islands of the Mediterranean, and founded a piratical state which became for him the source of enormous wealth during half a century, but for Italy and other countries of the coast one of indescribable devastations.
One hundred and seven years had the Vandal empire stood when, after the Germans had become greatly degenerated, it was overthrown with ease in the year 534 by Justinian’s general, Belisarius. Only indirectly, as lever and impelling force, had the incursions of the Huns from 375 onwards influenced the tribal migrations, particularly the entrance of the Germans into Gaul, Spain, and Africa.
It would seem as though the terrible Attila, that mighty scourge of God, had determined to complete the work of destruction. But Attila’s empire was built up on his personality; with his death it fell to pieces.
Therefore his campaigns of the years 451 and 452 in Gaul and Italy—with the battle at Châlons, so famous in the world’s history—were only a remarkable interlude in the great drama of race migration, and of no decisive import in its real progress. After Attila’s death, when Valentinian III had himself deprived the empire of its last support by the murder of Aëtius in 454, the decline of the Western Roman Empire set in, and continued during the next twenty years.
Not external pressure, whose severest shock had been happily averted, but the inward germ of death, the growing power of the barbarians within the empire itself, brought this occurrence, so important in the world’s history, to maturity. For centuries the Roman army had consisted for the most part of foreigners, chiefly Germans. With the need the number increased, and at the same time their self-confidence and pretensions, and consequently the hatred of the barbarians on the part of the Romans. So long as the son and grandson of Theodosius reigned, the great generals, by the habit of obedience and the magic of legitimate rights, masked the inner dissensions and the weakness of the empire. But when Nemesis had avenged the death of Aëtius on Valentinian III by his own death in a similar manner, the internal corruption of the state revealed itself under the growing pressure from without.