The Battle of the Catalaunian Plains (or Fields), also called the Battle of the Campus Mauriacus, Battle of Châlons, Battle of Troyes or the Battle of Maurica, took place on June 20, 451 AD, between a coalition – led by the Roman general Flavius Aetius and by the Visigothic king Theodoric I – against the Huns and their vassals – commanded by their king Attila. It proved one of the last major military operations of the Western Roman Empire, although Germanic foederati composed the majority of the coalition army.