Until 369 Emperor Valens waged war successfully against the Visigoths, who were led by Athanaric. Athanaric asserted his supremacy over Fritigern, a rival Visigothic leader who then retired into the Roman Empire and obtained Roman aid against Athanaric. However, the internal affairs of the Goths became of secondary importance to the invasion (c.375) of their lands by the Huns. Athanaric retired to Transylvania, and the majority of the Visigoths joined Fritigern and fled (376) into the empire. Subjected to oppressive measures by Roman officials, these Visigothic settlers soon rose in revolt. Opposed by Emperor Valens at Adrianople in 378, the Goths won a decisive victory. They then swept across the upper Balkan Peninsula and ravaged Thrace. Theodosius I immediately took up arms against them. In 382 peace was finally concluded, and the Goths under Athanaric were settled in Thrace. Friction, however, continued.

In 395, after the death of Theodosius I, the Visigothic troops in Roman service proclaimed Alaric I their leader; under his strong guidance they first developed the concept of kingship. Alaric led a revolt in the Balkan Peninsula but was checked by Stilicho. In 401 Alaric began his attacks on Italy; he was halted by Stilicho, but after Stilicho's death he succeeded in his invasion, and the Visigoths became masters of Italy. Negotiations between Alaric and Emperor Honorius failed, and in 410 the Visigoths sacked Rome. Alaric died soon afterward.

Under Ataulf the Visigoths left (412) Italy and went into S Gaul and N Spain. They increased their territories in Spain (which was evacuated by the Vandals), acquired Aquitaine, and extended their influence to the Loire valley, making Toulouse their capital. The height of Visigothic power was reached under Euric (466–84), who completed the conquest of Spain. In 507, Alaric II was defeated at Vouillé by the Franks under Clovis, to whom he lost nearly all his possessions N of the Pyrenees. Toledo became the new Visigothic capital, and the history of the Visigoths became essentially that of Spain.

Weakened by warfare with the Franks and the Basques and by Byzantine penetration in S Spain, the kingdom recovered its vigor in the late 6th cent. under Leovigild and under Recared, whose conversion to Catholicism facilitated the fusion of the Visigothic and the Hispano-Roman populations of Spain. King Recceswinth imposed (c.654) a Visigothic common law on both his Gothic and his Roman subjects, who previously had lived under different codes (see Germanic laws). The church councils of Toledo became the main force in the government, and the royal power was weakened accordingly.

King Wamba, who succeeded Recceswinth, was deposed after a civil war, and thereafter the kingdom was torn by civil strife. When the last king, Roderick, seized the throne, his rivals appealed to the Muslim leader Tarik ibn Ziyad, whose victory (711) in a battle near Medina Sidonia ended the Visigothic kingdom and inaugurated the Moorish period in the history of Spain.

See T. Hodgkin, Italy and Her Invaders, Vol. I–III (2d ed. 1892–96, repr. 1967); E. A. Thompson, The Goths in Spain (1969); A. Barbero, The Day of the Barbarians (2007).