Flavius Julius Constans ( 323 – 350), sometimes called Constans I, was
Roman emperor from 337 to 350. He held the imperial rank of ''
caesar
Gaius Julius Caesar (; ; 12 July 100 BC – 15 March 44 BC), was a Roman people, Roman general and statesman. A member of the First Triumvirate, Caesar led the Roman armies in the Gallic Wars before defeating his political rival Pompey in Caes ...
'' from 333, and was the youngest son of
Constantine the Great
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 Constantine the Great and Christianity, convert to Christiani ...
.
After his father's death, he was made ''
augustus'' alongside his brothers in September 337. Constans was given the administration of the
praetorian prefectures of
Italy,
Illyricum, and
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area ...
.
He defeated the
Sarmatians in a campaign shortly afterwards.
Quarrels over the sharing of power led to a civil war with his eldest brother and co-emperor
Constantine II, who invaded Italy in 340 and was killed in battle with Constans's forces near
Aquileia
Aquileia / / / / ;Bilingual name of ''Aquileja – Oglej'' in: vec, Aquiłeja / ; Slovenian: ''Oglej''), group=pron is an ancient Roman city in Italy, at the head of the Adriatic at the edge of the lagoons, about from the sea, on the river N ...
.
Constans gained from him the
praetorian prefecture of Gaul.
Thereafter there were tensions with his remaining brother and co-''augustus''
Constantius II (), including over the exiled bishop
Athanasius of Alexandria
Athanasius I of Alexandria, ; cop, ⲡⲓⲁⲅⲓⲟⲥ ⲁⲑⲁⲛⲁⲥⲓⲟⲩ ⲡⲓⲁⲡⲟⲥⲧⲟⲗⲓⲕⲟⲥ or Ⲡⲁⲡⲁ ⲁⲑⲁⲛⲁⲥⲓⲟⲩ ⲁ̅; (c. 296–298 – 2 May 373), also called Athanasius the Great, ...
.
In the following years he campaigned against the
Franks, and in 343 he visited
Roman Britain,
the last legitimate emperor to do so.
In January 350,
Magnentius () the commander of the
Jovians and Herculians, a corps in the
Roman army
The Roman army (Latin: ) was the armed forces deployed by the Romans throughout the duration of Ancient Rome, from the Roman Kingdom (c. 500 BC) to the Roman Republic (500–31 BC) and the Roman Empire (31 BC–395 AD), and its medieval continu ...
, was
acclaimed ''augustus'' at Augustodunum (
Autun) with the support of Marcellinus, the ''
comes rei privatae''.
Magnentius overthrew and killed Constans.
Surviving sources, possibly influenced by the propaganda of Magnentius's faction, accuse Constans of misrule and of homosexuality.
Early life
Constans was probably born in 323. He was the third and youngest son of Constantine I and
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 Zosimu ...
, his father's second wife.
[DiMaio, ''Constans I (337–350 A.D.)''] He was the grandson of both the ''augusti''
Constantius I and
Maximian
Maximian ( la, Marcus Aurelius Valerius Maximianus; c. 250 – c. July 310), nicknamed ''Herculius'', was Roman emperor from 286 to 305. He was ''Caesar'' from 285 to 286, then ''Augustus'' from 286 to 305. He shared the latter title with his ...
. When he was born his father Constantine was the empire's senior ''augustus'', and at war with his colleague and brother-in-law
Licinius I (). At the time of Constans's birth, his eldest brother
Constantine II and his half-brother
Crispus, Constantine's first-born son, already held the rank of ''caesar''. Constans's half-aunt
Constantia, a daughter of Constantius I, was Licinius's wife and mother to another ''caesar'',
Licinius II.
After the defeat of Licinius by
Crispus at the
Battle of the Hellespont
The Battle of the Hellespont, consisting of two separate naval clashes, was fought in 324 between a Constantinian fleet, led by the eldest son of Constantine I, Crispus; and a larger fleet under Licinius' admiral, Abantus (or Amandus). Despite ...
and at the
Battle of Chrysopolis by Constantine, Licinius and his son were spared at Constantine's half-sister's urging. Licinius was executed on a pretext shortly afterwards.
In 326, Constans's mother Fausta was also put to death on Constantine's orders, as were Constans's half-brother Crispus and Licinius II. This left Constans's branch of the
Constantinian dynasty – descended from
Constantius I's relationship with
Helena
Helena may refer to:
People
*Helena (given name), a given name (including a list of people and characters with the name)
*Katri Helena (born 1945), Finnish singer
*Helena, mother of Constantine I
Places
Greece
* Helena (island)
Guyana
* ...
– in control of the imperial college.
According to the works of both
Ausonius and
Libanius he was educated at
Constantinople
la, Constantinopolis ota, قسطنطينيه
, alternate_name = Byzantion (earlier Greek name), Nova Roma ("New Rome"), Miklagard/Miklagarth ( Old Norse), Tsargrad ( Slavic), Qustantiniya (Arabic), Basileuousa ("Queen of Cities"), Megalopolis ( ...
under the tutelage of the poet
Aemilius Magnus Arborius, who instructed him in Latin.
Reign
''Caesar''
On 25 December 333, his father Constantine I elevated Constans to the imperial rank of ''
caesar
Gaius Julius Caesar (; ; 12 July 100 BC – 15 March 44 BC), was a Roman people, Roman general and statesman. A member of the First Triumvirate, Caesar led the Roman armies in the Gallic Wars before defeating his political rival Pompey in Caes ...
'' at
Constantinople
la, Constantinopolis ota, قسطنطينيه
, alternate_name = Byzantion (earlier Greek name), Nova Roma ("New Rome"), Miklagard/Miklagarth ( Old Norse), Tsargrad ( Slavic), Qustantiniya (Arabic), Basileuousa ("Queen of Cities"), Megalopolis ( ...
. He was ''nobilissimus caesar'' alongside his brothers
Constantine II and
Constantius II. Constans became engaged to
Olympias
Olympias ( grc-gre, Ὀλυμπιάς; c. 375–316 BC) was a Greek princess of the Molossians, and the eldest daughter of king Neoptolemus I of Epirus, the sister of Alexander I of Epirus, the fourth wife of Philip II, the king of Macedonia a ...
, the daughter of the
praetorian prefect
The praetorian prefect ( la, praefectus praetorio, el, ) was a high office in the Roman Empire. Originating as the commander of the Praetorian Guard, the office gradually acquired extensive legal and administrative functions, with its holders be ...
Ablabius, but the marriage never came to pass.
Official imagery was changed to accommodate an image of Constans as co-''caesar'' beside his brothers and their father the ''augustus''.
It is possible that the occasion of Constans's elevation to the imperial college was timed to coincide with the celebration of the millennium of the city of
Byzantium
Byzantium () or Byzantion ( grc, Βυζάντιον) was an ancient Greek city in classical antiquity that became known as Constantinople in late antiquity and Istanbul today. The Greek name ''Byzantion'' and its Latinization ''Byzantium'' co ...
, whose re-foundation as
Constantinople
la, Constantinopolis ota, قسطنطينيه
, alternate_name = Byzantion (earlier Greek name), Nova Roma ("New Rome"), Miklagard/Miklagarth ( Old Norse), Tsargrad ( Slavic), Qustantiniya (Arabic), Basileuousa ("Queen of Cities"), Megalopolis ( ...
Constantine had begun the previous decade.
In 248, Rome had celebrated its own millennium, the
Secular Games (), in the reign of
Philip the Arab ().
Philip may also have raised his son to co-''augustus'' at the start of the anniversary year.
Rome had been calculated by the 1st-century BC Latin author
Marcus Terentius Varro to have been founded by
Romulus
Romulus () was the legendary foundation of Rome, founder and King of Rome, first king of Ancient Rome, Rome. Various traditions attribute the establishment of many of Rome's oldest legal, political, religious, and social institutions to Romulus ...
in 753 BC.
Byzantium was thought to have been founded in 667 BC by
Byzas, according to the reckoning derived from the ''
Histories
Histories or, in Latin, Historiae may refer to:
* the plural of history
* ''Histories'' (Herodotus), by Herodotus
* ''The Histories'', by Timaeus
* ''The Histories'' (Polybius), by Polybius
* ''Histories'' by Gaius Sallustius Crispus (Sallust), ...
'' of
Herodotus, the 5th-century BC Greek historian, and the writings of Constantine's court historian
Eusebius of Caesarea
Eusebius of Caesarea (; grc-gre, Εὐσέβιος ; 260/265 – 30 May 339), also known as Eusebius Pamphilus (from the grc-gre, Εὐσέβιος τοῦ Παμφίλου), was a Greek historian of Christianity, exegete, and Christia ...
in his
''Chronicon''.
''Augustus''
With Constantine's death in 337, Constans and his two brothers,
Constantine II and
Constantius II, divided the Roman world among themselves
[Eutropius, 10:9] and disposed of virtually all relatives who could possibly have a claim to the throne.
[Victor, 41:20] The army proclaimed them ''
augusti
''Augustus'' (plural ''Augusti''; , ; "majestic", "great" or "venerable") was an ancient Roman title given as both name and title to Gaius Julius Caesar Octavianus (often referred to simply as Augustus), Rome's first Emperor. On his death, it ...
'' on 9 September 337. Almost immediately, Constans was required to deal with a
Sarmatian invasion in late 337, in which he won a resounding victory.

Constans managed to extract the prefecture of
Illyricum and the
diocese of Thrace
The Diocese of Thrace ( la, Dioecesis Thraciae, el, Διοίκησις Θρᾴκης) was a diocese of the later Roman Empire, incorporating the provinces of the eastern Balkan Peninsula (comprising territories in modern south-eastern Romania, c ...
, provinces that were originally to be ruled by his cousin
Dalmatius, as per Constantine I's proposed division after his death.
Constantine II soon complained that he had not received the amount of territory that was his due as the eldest son.
[Gibbon, Ch. 18]
Annoyed that Constans had received Thrace and
Macedonia
Macedonia most commonly refers to:
* North Macedonia, a country in southeastern Europe, known until 2019 as the Republic of Macedonia
* Macedonia (ancient kingdom), a kingdom in Greek antiquity
* Macedonia (Greece), a traditional geographic reg ...
after the death of Dalmatius, Constantine demanded that Constans hand over the African provinces, which he agreed to do in order to maintain a fragile peace.
[Victor, 41:21] Soon, however, they began quarreling over which parts of the African provinces belonged to
Carthage and Constantine, and which parts belonged to
Italy and Constans. This led to growing tensions between the two brothers, which were only heightened by Constans finally coming of age and Constantine refusing to give up his guardianship. In 340 Constantine II invaded Italy.
Constans, at that time in
Dacia, detached and sent a select and disciplined body of his Illyrian troops, stating that he would follow them in person with the remainder of his forces.
Constantine was eventually trapped at
Aquileia
Aquileia / / / / ;Bilingual name of ''Aquileja – Oglej'' in: vec, Aquiłeja / ; Slovenian: ''Oglej''), group=pron is an ancient Roman city in Italy, at the head of the Adriatic at the edge of the lagoons, about from the sea, on the river N ...
, where he died, leaving Constans to inherit all of his brother's former territories –
Hispania,
Britannia
Britannia () is the national personification of Britain as a helmeted female warrior holding a trident and shield. An image first used in classical antiquity, the Latin ''Britannia'' was the name variously applied to the British Isles, Gr ...
and
Gaul.

Constans began his reign in an energetic fashion.
In 341–342, he led a successful campaign against the
Franks, and in the early months of 343 he visited
Britain, probably as part of a military campaign.
Regarding religion, Constans was tolerant of
Judaism and promulgated an edict banning pagan sacrifices in 341.
He suppressed
Donatism in Africa and supported
Nicene orthodoxy against
Arianism
Arianism ( grc-x-koine, Ἀρειανισμός, ) is a Christological doctrine first attributed to Arius (), a Christian presbyter from Alexandria, Egypt. Arian theology holds that Jesus Christ is the Son of God, who was begotten by God ...
, which was championed by his brother Constantius. Although Constans called the
Council of Serdica in 343 to settle the conflict, it was a complete failure, and by 346 the two emperors were on the point of open warfare over the dispute.
Homosexuality
Surviving sources, possibly influenced by the propaganda of Magnentius's faction, accuse Constans of misrule and of homosexuality.
The Roman historian
Eutropius says Constans "indulged in great vices," in reference to his
homosexuality, and
Aurelius Victor stated that Constans had a reputation for scandalous behaviour with "handsome barbarian hostages."
Nevertheless, Constans did sponsor a decree alongside Constantius II that ruled that marriage based on "unnatural" sex should be punished meticulously. However, according to
John Boswell, it was likely that Constans promulgated the legislation under pressure from the growing band of Christian leaders, in an attempt to placate public outrage at his own perceived indecencies.
Death
In the final years of his reign, Constans developed a reputation for cruelty and misrule. Dominated by favourites and openly preferring his select bodyguard, he lost the support of the
legions.
On 18 January 350, the general
Magnentius declared himself emperor at Augustodunum (
Autun) with the support of the troops on the
Rhine frontier and, later, the western provinces of the Empire. Constans was enjoying himself nearby when he was notified of the elevation of Magnentius.
Lacking any support beyond his immediate household,
he was forced to flee for his life. As he was trying to reach
Hispania, supporters of Magnentius cornered him in a fortification in Helena (
Elne
Elne (; ca, Elna ) is a commune in the Pyrénées-Orientales department in southern France.
It lies in the former province of Roussillon, of which it was the first capital, being later replaced by Perpignan. Its inhabitants are still called ...
) in the eastern
Pyrenees of southwestern
Gaul, where he was killed after seeking sanctuary in a temple. An alleged
prophecy at his birth had said Constans would die "in the arms of his grandmother". His place of death happens to have been named after
Helena
Helena may refer to:
People
*Helena (given name), a given name (including a list of people and characters with the name)
*Katri Helena (born 1945), Finnish singer
*Helena, mother of Constantine I
Places
Greece
* Helena (island)
Guyana
* ...
, mother of
Constantine and his own grandmother, thus realizing the prophecy.
Family tree
Emperors are shown with a rounded-corner border with their dates as
Augusti
''Augustus'' (plural ''Augusti''; , ; "majestic", "great" or "venerable") was an ancient Roman title given as both name and title to Gaius Julius Caesar Octavianus (often referred to simply as Augustus), Rome's first Emperor. On his death, it ...
, names with a thicker border appear in both sections
1: Constantine's parents and half-siblings
2: Constantine's children
See also
*
Itineraries of the Roman emperors, 337–361
A travel itinerary is a schedule of events relating to planned travel, generally including destinations to be visited at specified times and means of transportation to move between those destinations. For example, both the plan of a business trip ...
References
Sources
Primary sources
*
Zosimus''Historia Nova''II
*
Aurelius Victor,
Epitome de Caesaribus'
*
Eutropius''Breviarium ab urbe condita''
Secondary sources
* DiMaio, Michael;
Frakes, Robert ''Constans I (337–350 A.D.)'', ''
De Imperatoribus Romanis''
*
* Gibbon, Edward (1888) ''
The History of the Decline and Fall of the Roman Empire''
*
Norwich, John Julius (1989) ''
Byzantium: The Early Centuries'', Guild Publishing
External links
*
{{Authority control
320s births
350 deaths
4th-century Christians
4th-century murdered monarchs
4th-century Roman consuls
4th-century Roman emperors
Constantine the Great
Constantinian dynasty
Flavii
Julii
LGBT Roman emperors
Murdered Roman emperors
People executed by the Roman Empire
Sons of Roman emperors