Vandals, ancient Germanic tribe of Jutland (now in Denmark), who migrated to the valley of the Odra (Oder) River about the 5th century bc. During the 2nd and 3rd centuries ad they settled along the Danube River. They entered Gaul (now France) in 406, invaded Spain in 409, and fought in the latter country against both the Visigoths (another Germanic tribe) and the Romans. Gaiseric became king of the tribe in 428, and under him the Vandals achieved their greatest power. They moved to North Africa the following year and there defeated the Romans. Gaiseric's sovereignty was recognized by Roman emperor Valentinian III in 422. The Vandals predominated in what is now Algeria and northern Morocco by 435 and conquered Carthage in 439. Their navy ruled the western Mediterranean Sea, and they looted and plundered in Italy, including Rome in 477. The tribe was Arian and it dealt severely with Orthodox Christians. The Vandals' power began to decline after Gaiseric's death in 477, and in 534 they were defeated by the Byzantine general Belsarius. The modern usage of the word vandal reflects the dread and hostility the tribe precipitated in other people by their looting and plundering, especially in Rome.