Magnus Maximus (Latin: Flavius Magnus Maximus Augustus, Welsh: Macsen Wledig) (ca. 335 – August 28, 388) was Western Roman Emperor from 383 to 388.In 383 as commander of Britain, he usurped the throne against emperor Gratian; and through negotiation with emperor Theodosius I the following year he was made emperor in Britannia and Gaul – while Gratian's brother Valentinian II retained Italy, Pannonia, Hispania, and Africa.