Magnentius (Latin: Flavius Magnus Magnentius Augustus; c. 303 – August 11, 353) was a usurper of the Roman Empire from 350 to 353.

Flavius Magnus Magnentius
Usurper of the Roman Empire
Golden multiplus by Magnentius. Caption: DN. MAGNENTIVS P. F. AVG.
ReignJanuary 18, 350 – August 11, 353
SuccessorConstantius II
Samarobriva, Gaul
Died(353-08-11)August 11, 353 (aged 50)
Mons Seleucus
Full name
Flavius Magnus Magnentius
Regnal name
Imperator Caesar Flavius Magnus Magnentius Augustus

Early life and career

Born in Samarobriva (Amiens), Gaul, Magnentius was the commander of the Herculians and Jovians, the Imperial guard units.[1] When the army grew dissatisfied with the behavior of Emperor Constans, it elevated Magnentius at Autun on 18 January 350.[2] Constans was hunting near the Pyrenees away from his forces, when Magnentius' forces cornered and killed him at Helene (near Perpignan).[2]


Magnentius quickly attracted the loyalty of the provinces in Britannia, Gaul, and Hispania, in part because he proved to be far more tolerant towards both Christians and Pagans. His control of Italia and Africa was secured through the election of his men to the most important offices. However, the short-lived revolt of Nepotianus, a member of the Constantinian dynasty, showed Magnentius that his status as emperor needed to be consolidated.

Magnentius tried to strengthen his grasp on the territories previously controlled by Constans, moving towards the Danube. Vetranio, commander of the Pannonian army, had been elected Augustus by his troops in Mursa on 1 March. This revolt had a loyalist mark, since Vetranio was supported by Constantina, and Constantius II himself recognized Vetranio, sending him the imperial diadem.


The remaining emperor of the family of Constantine I, Constantius II, broke off his war with Persia, and marched west from Syria. Despite Magnentius' efforts to win Vetranio over to his cause, the elderly Vetranio reached Constantius with his army, resigned the crown, and went into retirement in Bithynia.

After electing Magnus Decentius (probably his brother) as Caesar and gathering as many troops as possible, Magnentius advanced his armies to meet those of Constantius in the Battle of Mursa Major in 351; Magnentius led his troops into battle, while Constantius spent the day of battle praying in a nearby church. Despite Magnentius' heroism, his troops were defeated and forced to retreat back to Gaul.

As a result of Magnentius' defeat, Italy ejected his garrisons and rejoined the loyalist cause. Magnentius made a final stand in 353 at the Battle of Mons Seleucus, after which he committed suicide by falling on his sword.

Following the suppression of Magnentius' rebellion, Constantius began to root out his followers. The most notorious agent he employed in this search was the primicerius notariorum Paulus Catena ("Paul the Chain").

Some sources state that Magnentius' father was a Briton and his mother a Frank.[2] His wife, Justina, later married Valentinian I.


  1. Zosimus, ii.58
  2. Crawford 2016, p. 71.


  • Cameron, Averil, and Peter Garnsey ed., The Cambridge Ancient History, Vol XIII, Cambridge University Press, 1988.
  • Crawford, Peter (2016). Constantius II: Usurpers, Eunuchs, and the Antichrist. Pen & Sword.
  • (in French) Pierre Bastien (numismat), Le Monnayage de Magnence (350 – 353), Wetteren (Belgium), Édition numismatique romaine, 1983

Media related to Magnentius at Wikimedia Commons

Born: 18 January 350 Died: 11 August 353
Regnal titles
Preceded by
Roman Emperor
Served alongside: Constantius II and Decentius as appointed Caesar (junior emperor)
Succeeded by
Constantius II
Political offices
Preceded by
Consul of the Roman Empire
with Gaiso
Succeeded by
Flavius Magnus Decentius Caesar,
Paulus ,
Flavius Iulius Constantius Augustus V,
Flavius Claudius Constantius Caesar
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.