Valentinian III
Petronius Maximus became the Western Roman Emperor on 17 March 455, after assassinating Valentinian III. During his short reign, he provoked Gaiseric, the Vandal king, into invading the Western Empire and sacking Rome, by breaking a marriage agreement made between Gaiseric and Valentinian III. Maximus and his son Palladius attempted to flee on 31 May 455, however they were apprehended by a group of peasants, and either killed by them, or by palace servants wishing to curry favor with them.