In the 440s, the Vandal king Genseric and the Roman Emperor Valentinian III, had betrothed their children, Huneric and Eudocia, to strengthen their alliance, reached in 442 with a peace treaty (the marriage was delayed as Eudocia was too young). In 455 Valentinian was killed, and Petronius Maximus rose to the throne. Petronius married Valentinian's widow, Licinia Eudoxia, and had his son Palladius marry Eudocia; in this way Petronius was to strengthen his bond with the Theodosian dynasty. This move, however, damaged Genseric's ambitions. The king of the Vandals claimed that the broken betrothal between Huneric and Eudocia was an invalidation of his peace treaty with Valentinian, and set sail to attack Rome.