Magnus Maximus (Latin: Flavius Clemens Magnus Maximus Augustus, Welsh: Macsen Wledig) (ca. 335 – August 28, 388), also known as Maximianus(not to be confused with the emperor Maximian), 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. In 387 Maximus’ ambitions led him to invade Italy, resulting in his defeat by Theodosius I at the Battle of the Save in 388. In the view of some historians his death marked the end of direct imperial presence in Northern Gaul and Britain.