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

Constantius II Constantius II (; ; 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 peoples, while internally the Roman Empire went through repeated civ ...

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 a ...

Magnentius Magnus Magnentius ( 303 – 10 August 353) was a Roman general and usurper against Constantius II. Of Germanic descent, Magnentius served with distinction in Gaul, where the army chose him as a replacement for the unpopular emperor Constans. Ac ...

Background

With the death of

Constantine I Constantine I (27 February 27222 May 337), also known as Constantine the Great, was a Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a Constantine the Great and Christianity, pivotal ro ...

in 337 AD, the

empire An empire is a political unit made up of several territories, military outpost (military), outposts, and peoples, "usually created by conquest, and divided between a hegemony, dominant center and subordinate peripheries". The center of the ...

was divided between his three sons from his marriage to

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

. Constantine II received

Gaul Gaul () was a region of Western Europe first clearly described by the Roman people, Romans, encompassing present-day France, Belgium, Luxembourg, and parts of Switzerland, the Netherlands, Germany, and Northern Italy. It covered an area of . Ac ...

Spain Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...

and

Britain Britain most often refers to: * Great Britain, a large island comprising the countries of England, Scotland and Wales * The United Kingdom of Great Britain and Northern Ireland, a sovereign state in Europe comprising Great Britain and the north-eas ...

was given

Asia Minor Anatolia (), also known as Asia Minor, is a peninsula in West Asia that makes up the majority of the land area of Turkey. It is the westernmost protrusion of Asia and is geographically bounded by the Mediterranean Sea to the south, the Aegean ...

Egypt Egypt ( , ), officially the Arab Republic of Egypt, is a country spanning the Northeast Africa, northeast corner of Africa and Western Asia, southwest corner of Asia via the Sinai Peninsula. It is bordered by the Mediterranean Sea to northe ...

and

Syria Syria, officially the Syrian Arab Republic, is a country in West Asia located in the Eastern Mediterranean and the Levant. It borders the Mediterranean Sea to the west, Turkey to Syria–Turkey border, the north, Iraq to Iraq–Syria border, t ...

. Finally,

Constans I Flavius Julius Constans ( 323 – 350), also 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 made ''a ...

obtained

Italy Italy, officially the Italian Republic, is a country in Southern Europe, Southern and Western Europe, Western Europe. It consists of Italian Peninsula, a peninsula that extends into the Mediterranean Sea, with the Alps on its northern land b ...

North Africa North Africa (sometimes Northern Africa) is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region. However, it is sometimes defined as stretching from the Atlantic shores of t ...

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

Augustus Gaius Julius Caesar Augustus (born Gaius Octavius; 23 September 63 BC – 19 August AD 14), also known as Octavian (), was the founder of the Roman Empire, who reigned as the first Roman emperor from 27 BC until his death in A ...

. 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 an administrative division within a country or sovereign state, state. The term derives from the ancient Roman , which was the major territorial and administrative unit of the Roman Empire, Roman Empire's territorial possessions ou ...

s of the empire. Constans grew unpopular with the

army An army, ground force or land force is an armed force that fights primarily on land. In the broadest sense, it is the land-based military branch, service branch or armed service of a nation or country. It may also include aviation assets by ...

, leading to a military conspiracy which overthrew and killed him in 350 AD. The soldiers elevated a

barbarian A barbarian is a person or tribe of people that is perceived to be primitive, savage and warlike. Many cultures have referred to other cultures as barbarians, sometimes out of misunderstanding and sometimes out of prejudice. A "barbarian" may ...

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," fro ...

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 armoured heavy cavalry that originated in Persia and was fielded in ancient warfare throughout Eurasia and Northern Africa. Historically, the cataphract was a very heavily armoured horseman, with both the rider and ...

cavalry Historically, cavalry (from the French word ''cavalerie'', itself derived from ''cheval'' meaning "horse") are groups of soldiers or warriors who Horses in warfare, fight mounted on horseback. Until the 20th century, cavalry were the most mob ...

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 commonly refers to: * Mons, Belgium, a city in Belgium * Mons pubis (mons Venus or mons veneris), in mammalian anatomy, the adipose tissue lying above the pubic bone * Mons (planetary nomenclature), a sizable extraterrestrial mountain * Batt ...

on 3 July 353. Magnentius fled to

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

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 including corporal punishment, punishment, forced confession, extracting a confession, interrogational torture, interrogation for information, or intimid ...

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