Placidia () was a daughter of Valentinian III, Roman emperor of the West from 425 to 455, and from 454/455 the wife of Olybrius, who became western Roman emperor in 472. She was one of the last imperial spouses in the Roman west, during the Fall of the Western Roman Empire during Late Antiquity. Biography In 455 she was taken prisoner in the Sack of Rome by Gaiseric, King of the Vandals, together with her mother Licinia Eudoxia and her elder sister Eudocia, spending several years in the Vandal Kingdom while Gaiseric promoted Olybrius's claim to the empire. Placidia and her mother were ransomed from Africa by Leo I, the eastern emperor, in . Placidia spent much of her life at Constantinople, where her daughter Anicia Juliana was born in and where she remained during her husband's brief reign as augustus in Rome. She was a nobilissima femina, known to have been living in Constantinople in 478 and 484. Family Placidia was the second daughter of Valentinian III and Licinia Eudoxia, younger sister of Eudocia, who became the wife of Huneric, son of Gaiseric, king of the Vandals. Both were named for their grandmothers: Eudocia for the maternal, Aelia Eudocia, and Placidia for the paternal, Galla Placidia. Placidia is estimated to have been born between 439 and 443. Marriage In 454 or 455, Placidia married Anicius Olybrius, a member of the Anicii family, a prominent family with known members active in both Italia and Gaul. The exact relation of Olybrius to other members of the family is not known as his parents are not named in primary sources. Several theories exist as to their identity. Originally Emperor Valentinian intended to marry Placidia to a young man named Majorian (the future emperor), whom Oost describes as having "distinguished himself in a subaltern capacity fighting in Gaul against the Franks under Aëtius' own command." Doing so, according to Roman customs, would instantly link Majorian to the Imperial family and put him in line to succeed Valentinian. Once Flavius Aetius learned of this plan, he rusticated Majorian to his estates at some date before 451, and he was recalled to Rome only after Aetius' death. Aetius also attempted to consolidate his position "by compelling the Emperor to swear to friendship with him and to agree to betroth Placidia to his own younger son Gaudentius." Mommaerts and Kelley have proposed a theory that Petronius