The Roman civil war of 350–353 AD was a war fought between the Roman emperor

Constantius II Constantius II (Latin: ''Flavius Julius Constantius''; grc-gre, Κωνστάντιος; 7 August 317 – 3 November 361) was Roman emperor from 337 to 361. His reign saw constant warfare on the borders against the Sasanian Empire and Germanic ...

and the

usurper A usurper is an illegitimate or controversial claimant to power, often but not always in a monarchy. In other words, one who takes the power of a country, city, or established region for oneself, without any formal or legal right to claim it as ...

Magnentius.

Background

With the death of

Constantine I Constantine I ( , ; la, Flavius Valerius Constantinus, ; ; 27 February 22 May 337), also known as Constantine the Great, was Roman emperor from AD 306 to 337, the first one to convert to Christianity. Born in Naissus, Dacia Mediterran ...

in 337 AD, the

empire An empire is a "political unit" made up of several territories and peoples, "usually created by conquest, and divided between a dominant center and subordinate peripheries". The center of the empire (sometimes referred to as the metropole) ex ...

was divided between his three sons from his marriage to

Fausta Flavia Maxima Fausta ''Augusta'' (289–326 AD) was a Roman empress. She was the daughter of Maximian and second wife of Constantine the Great, who had her executed and excluded from all official accounts for unknown reasons. Historians Zosim ...

. Constantine II received

Gaul Gaul ( la, Gallia) was a region of Western Europe first described by the Romans. It was inhabited by Celtic and Aquitani tribes, encompassing present-day France, Belgium, Luxembourg, most of Switzerland, parts of Northern Italy (only during ...

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = '' Plus ultra'' (Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , ...

and

Britain Britain most often refers to: * The United Kingdom, a sovereign state in Europe comprising the island of Great Britain, the north-eastern part of the island of Ireland and many smaller islands * Great Britain, the largest island in the United King ...

was given

Asia Minor Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...

Egypt Egypt ( ar, مصر , ), officially the Arab Republic of Egypt, is a List of transcontinental countries, transcontinental country spanning the North Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via a land bridg ...

and

Syria Syria ( ar, سُورِيَا or سُورِيَة, translit=Sūriyā), officially the Syrian Arab Republic ( ar, الجمهورية العربية السورية, al-Jumhūrīyah al-ʻArabīyah as-Sūrīyah), is a Western Asian country loc ...

. Finally,

Constans I Flavius Julius Constans ( 323 – 350), sometimes called Constans I, was Roman emperor from 337 to 350. He held the imperial rank of ''caesar'' from 333, and was the youngest son of Constantine the Great. After his father's death, he was mad ...

obtained

Italy Italy ( it, Italia ), officially the Italian Republic, ) or the Republic of Italy, is a country in Southern Europe. It is located in the middle of the Mediterranean Sea, and its territory largely coincides with the homonymous geographical ...

North Africa North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in ...

and Illyricum. Constantine II resented his brothers for not respecting his seniority as the eldest, and therefore the senior

Augustus Caesar Augustus (born Gaius Octavius; 23 September 63 BC – 19 August AD 14), also known as Octavian, was the first Roman emperor; he reigned from 27 BC until his death in AD 14. He is known for being the founder of the Roman Pr ...

. Unhappy over the distribution of the provinces, he invaded Italy in 340 AD, only to be killed in an ambush by Constans' troops. Constans now assumed control of all the western

province A province is almost always an administrative division within a country or state. The term derives from the ancient Roman ''provincia'', which was the major territorial and administrative unit of the Roman Empire's territorial possessions out ...

s of the empire. Constans was particularly disliked by the

legion Legion may refer to: Military * Roman legion, the basic military unit of the ancient Roman army * Spanish Legion, an elite military unit within the Spanish Army * Legion of the United States, a reorganization of the United States Army from 179 ...

s, and in 350 AD, he was overthrown by a military conspiracy and killed while fleeing to safety. The army elevated a

barbarian A barbarian (or savage) is someone who is perceived to be either uncivilized or primitive. The designation is usually applied as a generalization based on a popular stereotype; barbarians can be members of any nation judged by some to be less ...

officer An officer is a person who has a position of authority in a hierarchical organization. The term derives from Old French ''oficier'' "officer, official" (early 14c., Modern French ''officier''), from Medieval Latin ''officiarius'' "an officer," f ...

called Magnentius as the new western emperor, bringing him into conflict with Constantius, the sole remaining son of Constantine I.

Civil war

Constantius marched westward to avenge the murder of his brother. Magnentius decided to invade Illyricum, and initially his army performed very well. The situation changed dramatically when his troops encountered Constantius'

cataphract A cataphract was a form of armored heavy cavalryman that originated in Persia and was fielded in ancient warfare throughout Eurasia and Northern Africa. The English word derives from the Greek ' (plural: '), literally meaning "armored" or ...

cavalry Historically, cavalry (from the French word ''cavalerie'', itself derived from "cheval" meaning "horse") are soldiers or warriors who fight mounted on horseback. Cavalry were the most mobile of the combat arms, operating as light cavalry in ...

at the Battle of Mursa on 28 September 351. The fighting involved 95,000 troops and left 55,000 casualties in one of the bloodiest battles in Roman history. Magnentius lost and fled to northern Italy, while Constantius slowly regained control of Africa, Spain, and southern Italy. Magnentius decided to retreat into Gaul, where Constantius defeated him again at

Mons Seleucus Mons (; German and nl, Bergen, ; Walloon and pcd, Mont) is a city and municipality of Wallonia, and the capital of the province of Hainaut, Belgium. Mons was made into a fortified city by Count Baldwin IV of Hainaut in the 12th century. ...

on 3 July 353. Magnentius fled to

Lugdunum Lugdunum (also spelled Lugudunum, ; modern Lyon, France) was an important Roman city in Gaul, established on the current site of Lyon. The Roman city was founded in 43 BC by Lucius Munatius Plancus, but continued an existing Gallic settle ...

and committed suicide with his sword on 11 August 353. Constantius had Magnentius' followers and supporters investigated,

torture Torture is the deliberate infliction of severe pain or suffering on a person for reasons such as punishment, extracting a confession, interrogation for information, or intimidating third parties. Some definitions are restricted to acts ...

d and killed.

References

*Kohn, George Childs, 'Dictionary of Wars, Revised Edition', pg 399 {{DEFAULTSORT:Roman civil war of 350-351 Roman civil war of 350–353 Civil wars of the Roman Empire 350 351 350s in the Roman Empire Wars of succession involving the states and peoples of Asia 352 353 Wars of succession involving the states and peoples of Europe Wars of succession involving the states and peoples of Africa Constantius II