Roman Emperor - Magnus Maximus
Magnus Clemens Maximus, native of Spain, born to a poor family. He accompanied Theodosius on several military expeditions including Africa and the Danube. As a distinguished general he became commander of the troops in Britain, where he operated successfully against the Picts and Scots.
He pursued his imperial ambitions by taking a large number of British troops to Gaul while the Emperor Gratian was repelling an Alamannic invasion in Raetia.
Both forces met at Paris but Gratian's legions changed to Maximus's side. The emperor fled and he was overtaken and killed at Lyons.
Maximus was proclaimed emperor by the troops and Gaul, Spain, and Britain acknowledged Maximus as their ruler and took up his residence at Trier.
Maximus then entered into negotiations with Theodosius I to be recognized as emperor. Theodosius feared for the safety of Valentinian II in Italy, who was only aged 12. And had concerns with the dangers that threatened his eastern frontier
Theodosius wanted avoid war and therefore recognized Maximus as emperor.
Maximus negotiated with Valentinian II and made an uneasy peace which was just a temporary truce.
Maximus elevated his son Flavius Victor to co-ruler, and this elevation was recognized by the other two emperors.
Maximus made Augusta Treverorum (Treves, Trier) in Gaul his capital and ruled Gaul, Britain, Spain and Africa. He reorganized Gaul's system of provinces amd issued coinage. He utilized barbarian forces for his own benefit.
In 387 he crossed the Alps and invaded Italy, defeated Valentinian II and established himself in Milan. He had hoped to capture Valentinian himself, but Valentinian fled to Theodosius.
Despite all this Maximus had hoped to keep the peace with Theodosius, but the combined troops of Theodosius I and Valentinian II led by the general Richomeres then invaded from the east and campaigned against Magnus Maximus, who was was defeated in the Battle of the Save. He retreated to Aquileia.
As he had done with Gratian, Maximus hoped to win over the army of Theodosius, but only a few of the enemy's troops defected.
A series of battles took place and he was eventually but was defeated by Theodosius at Sixia, on the Saone and again at Poetovio on the Danube, being subsequently captured and put to death at Aquileia. His son Victor was also executed. His mother and at least two daughters were spared.
Encyclopaedia Britannica, Volume 22. 1971. Page 3.
New Age Encyclopaedia, Seventh Edition edited by D. A. Girling, Bay Books, 1983. Volume 19, Page 55.
Encyclopedia Americana, Volume 9, Americana Corporation, 1976.