During the first half of the 5th century the barbarians gradually installed themselves, in spite of the efforts of the Roman general Aetius at the head of a small army of mercenaries and of Huns. Aetius took back Arles and Narbonne from the Visigoths in 436, either pushed back the Salian and Ripuarian Franks beyond the Rhine or incorporated them as federates, settled the defeated Burgundians in Sapaudia (Savoy), and established the Alani in Orléans. The other provinces were lost: Britain, having been abandoned in 407 and already invaded by the Picts and Scots, fell to the Angles, Saxons, and Jutes; a great Suebi kingdom, officially federated but in fact independent, was organized in Spain after the departure of the Vandals, and it allied itself to the Visigoths of Theodoric I, who were settled in the country around the Garonne.

In 428 the Vandal Gaiseric led his people (80,000 persons, including 15,000 warriors) to Africa. St. Augustine died in 430 in besieged Hippo, Carthage fell in 435, and in 442 a treaty gave Gaiseric the rich provinces of Byzacena and Numidia. From there he was able to starve Rome, threaten Sicily, and close off the western basin of the Mediterranean to the Byzantines.
Shortly afterward, in 450, Attila’s Huns invaded the West—first Gaul, where, after having been kept out of Paris, they were defeated by Aetius on the Campus Mauriacus (near Troyes), then Italy, which they evacuated soon after having received tribute from the pope, St. Leo. Attila died shortly afterward; and this invasion, which indeed left more legendary memories than actual ruins, had shown that a solidarity had been created between the Gallo-Romans and their barbarian occupiers, for the Franks, the Alemanni, and even Theodoric’s Visigoths had come to Aetius’ aid.

After the death of Aetius, in 454, and of Valentinian III, in 455, the West became the stake in the intrigues of the German chiefs Ricimer, Orestes, and Odoacer, who maintained real power through puppet emperors. In 457–461 the energetic Majorian reestablished imperial authority in southern Gaul until he was defeated by Gaiseric and assassinated shortly afterward. Finally, in 476, Odoacer deposed the last emperor, Romulus Augustulus, had himself proclaimed king in the barbaric fashion, and governed Italy with moderation, being de jure under the emperor of the East. The end of the Roman Empire of the West passed almost unperceived.

Barbarian kingdoms
Several barbarian kingdoms were then set up: in Africa, Gaiseric’s kingdom of the Vandals; in Spain and in Gaul as far as the Loire, the Visigothic kingdom; and farther to the north, the kingdoms of the Salian Franks and the Alemanni. The barbarians were everywhere a small minority. They established themselves on the great estates and divided the land to the benefit of the federates without doing much harm to the lower classes or disturbing the economy. The old inhabitants lived under Roman law, while the barbarians kept their own “personality of laws,” of which the best-known is the judicial composition, the Wergild. Romans and barbarians coexisted but uneasily. Among the obstacles to reconciliation were differences in mores; social and political institutions (personal monarchies, fidelity of man to man); language, although Latin was still used in administration; and above all religion: the Arianism of the barbarians permitted the Roman Catholic bishops to retain their hold over their flocks. The only persecution, however, was under the Vandals, whose domination was the harshest.

Two great kingdoms marked the end of the 5th century. In Gaul, Clovis, the king of the Salian Franks (reigned 481/482–511), expelled Syagrius, the last Roman, from Soissons, took Alsace and the Palatinate from the Alemanni (496), and killed Alaric II, king of the Visigoths, at Vouillé (507). His conversion to Catholicism assured him the support of the bishops, and Frankish domination was established in Gaul. At the same time, Theodoric, king of the Ostrogoths, reigned in Italy. He had been charged by the emperor Zeno to take back Italy from Odoacer in 488, and in 494 he had himself proclaimed king at Ravenna. His Goths, few in number, were established in the north; elsewhere he preserved the old imperial administration, with senators as prefects. Externally, he kept Clovis from reaching the Mediterranean and extended his state up to the valley of the Rhône. Theodoric died in 526. Ten years later Justinian charged his general Belisarius with the reconquest of Italy, a costly, devastating, and temporary operation that lasted from 535 to 540.