23. A solidus of Valentinian III. In order to secure the Theodosian dynasty, the only 6 year-old boy Valentinian was appointed Emperor of the Western Roman Empire. During his thirty-years reign he always strived to preserve peace with the Eastern Roman Empire. However, the Emperor was extremely challenged during the period of upheaval and migration. In spite of the historically significant victory over Attila the Hun in the battle of the Catalonian Plains in the year 451, Valentinian III was unable to stabilise his Empire.