After his father's death, he was madeaugustus alongside his brothers in September 337. Constans was given the administration of thepraetorian prefectures ofItaly,Illyricum, andAfrica.[4] He defeated theSarmatians in a campaign shortly afterwards.[4] Quarrels over the sharing of power led to a civil war with his eldest brother and co-emperorConstantine II, who invaded Italy in 340 and was killed in battle by Constans's forces nearAquileia.[4] Constans gained from him thepraetorian prefecture of Gaul.[4] Thereafter there were tensions with his remaining brother and co-augustusConstantius II (r. 337–361), including over the exiled bishopAthanasius of Alexandria,[4] who in turn eulogized Constans as "the most pious Augustus... of blessed and everlasting memory."[5] In the following years he campaigned against theFranks, and in 343 he visitedRoman Britain,[4] the last legitimate emperor to do so.[6]
In January 350,Magnentius (r. 350–353) the commander of theJovians and Herculians, a corps in theRoman army, wasacclaimedaugustus at Augustodunum (Autun) with the support of Marcellinus, thecomes rei privatae.[7] Magnentius overthrew and killed Constans.[4][7] Surviving sources, possibly influenced by the propaganda of Magnentius's faction,[8] accuse Constans of misrule and of homosexuality.[4]
Sources variously report Constans' age at the time of his death as 27 or 30, meaning he was born in either 320 or 323.[3]Timothy Barnes, observing numismatic evidence, considered the younger age to be more likely.[9] He was the third and youngest son of Constantine I andFausta.[10] According to the works of bothAusonius andLibanius, he was educated atConstantinople under the tutelage of the poetAemilius Magnus Arborius, who instructed him in Latin.[3]
On 25 December 333, Constans was elevated to the imperial rank ofcaesar atConstantinople by his father.[3] Prior to 337, Constans became engaged toOlympias, the daughter of thepraetorian prefectAblabius, although the two never actually married.[10]
Possible head of Constans from around his proclamation asaugustus.[11][12]Solidus of Constans marked:constans augustus.
After Constantine's death, Constans and his two brothers,Constantine II andConstantius II were proclaimedaugusti and divided the Roman empire among themselves on 9 September 337.[3] Constans was left with Italy, Africa and Illyricum.[13] In 338, he campaigned against theSarmatians.[14]
Meanwhile, Constans came into conflict with his eldest brother Constantine II over the latter's presumed authority over Constans' territory. After attempting to issue legislation to Africa in 339, which was part of Constans' realm, Constantine led his army into an invasion of Italy only a year later. However, he was ambushed and killed by Constans' troops, and Constans then took control of his brother's territories.[14]
Constans began his reign in an energetic fashion.[15][16] From 341 to 342, he led a campaign against theFranks where, after an initial setback,[17] the military operation concluded with a victory and a favorable peace treaty.[18]Eutropius wrote that he "had performed many gallant actions in the field, and had made himself feared by the army through the whole course of his life, though without exercising any extraordinary severity,"[19] whileAmmianus Marcellinus remarked thatJulian was the only person the Alamanni feared after the death of Constans.[18]
In the early months of 343, he visitedBritain, an event celebrated enough for Libanius to dedicate several sections of his panegyric to explaining it.[18] Although the reasons for the visit remain unclear,[20] the ancient writers were primarily interested in Constans' precarious journey to the province, rather than his actions within it.[18] One theory considers it to have involved the northern frontier, based on Ammianus' remark that he had discussed theAreani in his now-lost coverage of Constans' reign. Additionally, after recording attacks "near the frontiers" in 360, the historian wrote that the Alamanni were too much of a threat for Julian to confront the problem, in contrast to what Constans was able to do.[20]
Constans was accused of employing corrupt ministers during his reign, due to his purported personal greed.[21][22][23] One example included themagister officiorum (master of the offices) Flavius Eugenius, who remained in his position throughout most of the 340s.[24] Despite Eugenius being alleged to have misused his power to seize property,[24] the emperor continued to support him, his trust going as far as to honor him with a statue in theForum of Trajan inRome.[25]
Solidus of Constans marked:constansp·f· augustus on the obverse, with the emperor holding avexillum with achi-rho and crowned byVictory on the reverse, marked:spes rei publicae ("the hope of the Republic")
Constans issued an edict banning superstition and pagan sacrifices in 341,[26] his justification being that he was following the precedent set by his father.[27] Only a short while later though, he tried to moderate his stance by legislating against the destruction of temple buildings.[28]
Constans' support ofNicene orthodoxy and the bishopAthanasius of Alexandria brought him into conflict with his brother Constantius. Although the two emperors called theCouncil of Serdica in 343 to settle the conflict, it was a complete failure,[29] and by 345 Constans was outright threatening civil war against his brother.[30] Eventually, Constantius agreed to allow Athanasius to return to his position, as the bishop's replacement had recently died.[31] Constans also used the military to suppressDonatism in Africa, where the church was split between Donatists and Catholics.[31]
Unlike Constantius,[32] Constans was targeted with gossip over his personal life.[33] Numerous sources suspected him of homosexuality,[23] presumably based on the fact that he never married.[22]Aurelius Victor charged Constans with "rabid"[21]pederasty towards young barbarian hostages,[33] though Hunt remarked that "the allegation that he kept a coterie of captive barbarians to gratify his homosexual tastes sounds more like hostile folklore."[34] Constans' legislation against homosexuality has been cited to dispute the rumor.[34][35]
On 18 January 350,[36] the generalMagnentius declared himself emperor at Augustodunum (Autun) with the support of a number of court officials such asMarcellinus, Constans'comes rerum privatarum, as well asFabius Titianus, who had previously served as the praetorian prefect of Gaul.[34] At the time, Constans was distracted by a hunting trip.[37] As he was trying to reachHispania, supporters of Magnentius cornered him in a fortification in Helena (Elne) in the easternPyrenees of southwesternGaul, where he was killed after seeking sanctuary in a temple.[10][a] An allegedprophecy at his birth had said Constans would die "in the arms of his grandmother". His place of death happens to have been named afterHelena, mother ofConstantine and his own grandmother, thus realizing the prophecy.[40] Constans' name would later beerased from inscriptions in places that recognized Magnentius as emperor.[41]
Regarding possible motives for Constans' overthrow, ancient sources assert that he was widely unpopular,[21][34][42] and attribute his downfall to his own failings. Along with the accusation of corruption, he is also accused of neglecting portions of the empire[34] and treating his soldiers with contempt.[22][15] Ammianus lamented the emperor's failure to listen to wise counsel,[34] referencing one man he believed could have saved Constans from his own faults.[23]
However, some modern scholars have questioned this portrayal. According to historianJill Harries, "The detail that Constans was in the habit of making journeys with only a small escort may account for his vulnerability in 350."[22] Based on several factors - the small number of people behind the plot, how the setting for Magnentius' coup was not a military centre,[37]Vetranio's proclamation as emperor in opposition to Magnentius,[43] and Julian's report that the usurper had to murder several of Constans' generals to take control of the Gallic army[44] – she concluded that Magnentius' revolt was "the result of a private grudge on the part of an apprehensive official and not the outcome of widespread discontent among the military or the wider population."[45] This view is supported by Peter Crawford, who considered the explanation from the ancient sources to be a misconception caused by the rapid success of the coup.[46]
Harries does, however, acknowledge how the Gallic army accepted Magnentius seemingly without difficulty, and how according toZosimus, Constantius' official Philippus emphasized Constantine, rather than Constans, when addressing Magnentius' troops.[47] On speculating the basis for Constans' overthrow, she suggested that one reason may have been regarding financial difficulties in Gaul by the end of his reign, which could have been related to the finance officer Marcellinus' support of him.[44] After Magnentius took power, he levied taxes, sold imperial estates in Gaul and debased the coinage.[48] Nicholas Baker-Brian also observed how Magnentius sent his brotherDecentius to defend the region after Constans had neglected it, writing that, "it is apparent that among the reasons for Magnentius' rebellion was a desire to remedy Constans' governmental failings in Gaul."[49]
^While it has sometimes been assumed that Constans had to flee for his life,[10][38][21] Harries has disputed this, believing that the location of Constans' death indicates he was unaware of the revolt.[39]