Magnus Maximus (; ; died 28 August 388) was Roman emperor of the Western Roman Empire from 383 to 388. He usurped the throne from emperor Gratian.
He was made emperor in Britannia and Gaul the next year while Gratian's brother Valentinian II retained Italy, Pannonia, Hispania, and Africa. In 387, Maximus's ambitions led him to invade Italy, resulting in his defeat by Theodosius I at the Battle of Poetovio in 388. In the view of some historians, his death marked the end of direct imperial presence in Northern Gaul and Britannia.
Life
Birth, army career
Maximus was born in Gallaecia Hispania, on the estates of Count Theodosius (the Elder) of the Theodosian dynasty, to whom he claimed to be related. Most of his early life is unknown as the earliest mention of him in the historical record was of him being a junior officer possibly in Britain in 368 during the Great Conspiracy as he assisted Theodosius in defeating barbarians and criminals in Britannia. Maximus would become a distinguished general in the following years; as he would gain the support of his fellow soldiers and the admiration of the Romano-Britons whom he defended, which would lead to his eventual immortalisation in Welsh legend in the centuries following. He served under Count Theodosius in Africa in 373. Assigned to Britain in 380, he defeated an incursion of the Picts and Scots in 381.
Rebellion and bid for the throne
The Western emperor Gratian had received a number of Alans into his bodyguard, and was accused of showing favouritism towards these Iranian speaking foreigners at the expense of Roman citizens. In 383 the discontented Roman army proclaimed Maximus emperor in Gratian's place.
Maximus went to Gaul to pursue his imperial ambitions, taking a large portion of the British garrison with him. After five days of skirmishing near Paris he defeated Gratian, who fled the battlefield and was killed at Lyon on 25 August 383. Continuing his campaign into Italy, Maximus was stopped from overthrowing Valentinian II, who was only twelve, when Bauto came with a powerful force to forestall him. Negotiations followed in 384, including the intervention of Ambrose, Bishop of Milan, leading to an accord with Valentinian II and Theodosius I in which Maximus was recognized as Augustus in the West.
Administration
Maximus made his capital at Augusta Treverorum (Treves, Trier) in Gaul, and ruled Britain, Gaul, Spain and Africa. He issued coinage and a number of edicts reorganising Gaul's system of provinces. Some historians believe Maximus may have founded the office of the Comes Britanniarum as well, although it was probably Stilicho who created the permanent office.
Maximus was a stern persecutor of heretics. It was on his orders that Priscillian and six companions were executed for heresy, although the actual civil charges laid by Maximus were for the practice of magic. Prominent churchmen such as St. Ambrose and St. Martin of Tours protested against this involvement of the secular power in doctrinal matters, but the executions were carried out nonetheless. Maximus thereby not only established his credentials as an upholder of orthodoxy, but also strengthened his financial resources in the ensuing confiscations. The Gallic Chronicle of 452 describes the Priscillianists as "Manichaeans", a different Gnostic heresy already condemned in Roman law under Diocletian, and states that Magnus Maximus had them "caught and exterminated with the greatest zeal".
In a threatening letter addressed to Valentinian II, most likely composed between the spring of 384 and the summer of 387, Maximus complains of Valentinian's actions towards Ambrose and adherents of the Nicean Creed, writing: "Can it be that Your Serenity, venerable to me, thinks that a religion which has once taken root in the minds of men, which God himself has established, can be uprooted?" in response to "the disturbance and convulsion of Catholic law."
Conversely, Maximus's edict of 387/388, which censured Christians at Rome for burning down a Jewish synagogue, was condemned by bishop Ambrose, who said people exclaimed, "the emperor has become a Jew".
Final conflicts and execution
In 387, Maximus managed to force emperor Valentinian II out of Milan. Valentinian fled to Theodosius I, and the two subsequently invaded from the east; their armies, led by Richomeres and other generals, campaigned against Maximus in July–August 388. Maximus was defeated in the Battle of Poetovio, and retreated to Aquileia. Meanwhile, the Franks under Marcomer had taken the opportunity to invade northern Gaul, at the same time further weakening Maximus's position.