Gaiseric, also Genseric (400?-77), king of the Vandals (428-77) at the time of their greatest power. The illegitimate son of Godigiselus, leader of the Vandals during the invasion of Gaul, Gaiseric succeeded his brother Gunderic (reigned 406-28) in 428. The next year he led all his people from Spain to Africa. The Roman general in Africa, Bonifacius, tried vainly to turn the
Vandals back, but was defeated and forced to flee to Italy. After a triumphant progress across northern Africa, the Vandals captured Carthage in 439, and Gaiseric made the city his capital. Vandal fleets raided Sicily, Sardinia, and Corsica. In 455 Gaiseric used the death of the Roman emperor Valentinian III as a pretext for the invasion of Rome. The city was undefended, and the Vandals entered it peacefully, pillaged it for 14 days, and carried away its treasures. When he withdrew, Gaiseric took as hostages Valentinian's widow, the empress Eudoxia, and her two daughters, along with Roman citizens, who were treated as slaves. He then led his armies eastward, laying waste to Greece and Dalmatia and threatening Constantinople. Two major attempts to subdue the Vandals, by the Western Roman emperor Majorian (reigned 457-61) in 457 and by the Eastern Roman emperor Leo I in 468, were unsuccessful. The Eastern emperor Zeno was forced to recognize Gaiseric and make peace with him in 476. Gaiseric was succeeded by his son Hunneric (reigned 477-84), under whom the African empire of the Vandals began to disintegrate.