Ancient History & Civilisation

Chapter Fourteen

The Consequences of Constantine

Constantine’s progressive elimination of those emperors who had been set in place by Diocletian’s scheme took a decade and a half, from 308 to 324. His territorial expansion of authority involved a series of civil wars, the very sort of fighting that Diocletian’s scheme had been intended to avoid. Constantine was the cause of many Roman and imperial deaths, but he was also powerfully assisted by Licinius, who defeated and killed Maximin Daia in 313 and then also set about eliminating any claimants he could reach: Galerius died in 311, and his wife Valeria (Diocletian’s daughter) and son Candidianus, Diocletian’s widow Prisca, Severus’ son, and Maximin Daia’s son were all killed soon after. Diocletian had probably died in 311 and this seems to have been the signal for all this bloodletting. Licinius and Constantine fought their first war in 316 and Licinius lost. He promoted Aurelius Valerius Valens as his colleague for a time during the crisis, but then executed him at the peace. Eight years later, he faced another defeat and this time promoted a man called Marcus Martinianus, who again lasted only until Licinius’ new defeat. Both of these were Augusti; both Licinius and Martinianus were then executed by Constantine later in 324. Constantine finally cleared the board, copying Lucinius in his executions.1 This was the most prolonged period of civil warfare since the end of the Republic.

When Constantine had finished, in 324, he then had to devise a replacement for Diocletian’s system. Given that he had become emperor by a device of his father, in order that the son should succeed the father, it is no surprise that his own preference should be for hereditary succession. This had become clear by 310, when he ‘revealed’ that he was descended from the Emperor Claudius Gothicus (268–270).2 In other words, he claimed not to owe his throne merely to his selection by a previous Augustus, but to being the son and grandson of emperors. Furthermore, Constantine, almost unique among Roman emperors, had the children to make such a scheme work, or so it seemed.

Heredity had, of course, been in the background of every development or change in the system of succession since Augustus. Every emperor with children had intended to be the founder of a dynasty. Until Constantine none had succeeded beyond a single generation in a direct line, though it was certainly the case that several dynasties of a very complicated constitution can be discerned. These constructed dynasties, however, were more the product of ambition among relatives than procreation.

Augustus, Vespasian, Marcus Aurelius and Septimius had all established their families on the throne and passed it to their chosen family successors, but after one more generation the line had failed. (None of Augustus’ ‘dynasty’ ever even succeeded in delivering the throne to a son, and it is only with some expansion and manipulation of the family tree that his successors can be described as a dynasty; see Genealogical Table I.) The deaths of Domitian and Caracalla ended their direct lines, and it is very difficult to see the later Severans as being of a single family linked to Septimius (see Genealogical Table XI). During the rapid turnover of emperors in the seven decades between the death of Alexander Severus and the accession of Constantine, several other dynasties began, such as the Gordians (Genealogical Table XII), and the Licinians (Genealogical Table XIII) lasting several years, but others quickly failed without having really got started: those of Philip, Claudius II, Carus and Tacitus; in several cases, it seems as though a particular man was made emperor because he had a son who might inherit. In other words, dynasticism was frequently the preferred system, though if a family became established as rulers, this would exclude others and this prospect helped to arouse opposition.

These families do, in fact, often look more like a sequence of pseudo-dynasties rather than an actual dynasty. This must be seen as typically Roman, or rather, perhaps, as the imperial Roman version of dynastic succession. The aim was often direct succession from father to son, but the achievement was always actually a sequence of rulers who were linked by blood, adoption or marriage but only rarely by direct succession. If these more diffuse connections are included then we can see a succession of such dynasties: Julio-Claudian-Antonian-Domitianic, the Antonines from Nerva to Commodus (Genealogical Table VIII), and the Severans from Septimius to Alexander. Further, there was often a tendency to seek links backwards in time, as when Septimius adopted himself retrospectively into the Antonine dynasty, or when Elagabalus and then Alexander were announced to be the sons of Caracalla. Constantine’s retrospective recruitment of Claudius Gothicus into his ancestry was part of a Roman imperial tradition, therefore. It seems unlikely that such manipulations of ancestry were ever very convincing, either to the manipulator or to anyone else.

In this sequence, it is the Flavian dynasty that stands out as anomalous, in which two generations, the father and his sons, ruled in succession. Yet even here, had the dynasty continued, Domitian’s eventual chosen heirs were his second cousins and so at some considerable distance, genealogically, from him. So the family’s anomaly is the result of brevity, not success. (Of the other direct succession, Marcus to Commodus lasted only a little longer than the Flavians: thirty-one years to 27; the Severans, Septimius to Caracalla lasted twenty-six years; the Licinians lasted only fifteen; the family of Carus only three.) Hereditary succession was always the preferred system, at least among the emperors, but it was too often frustrated by those who would therefore be excluded from the possibility of succeeding. Nevertheless it was hereditary succession that was the norm in the wider society and it is hardly surprising that it eventually emerged as the preferred imperial system. The surprise is, perhaps, that it had taken so long.

It was, perhaps, another old Roman tradition that contributed to the long delay. Access to Roman magistrates in the Republic had been easy: they could be intercepted in the street, they could be visited in their homes, or they could be interrogated on the public platform. This openness continued under the Empire, making it all too easy to murder or assassinate emperors. Even the paranoid Domitian had fallen to a fairly obvious conspiracy involving Guardsmen, consuls, senators, officials and servants; the same may be said of Commodus, Caracalla and others. All these plotters had easy access, which they abused. When the military monarchy of Trajan emerged, the danger was surely all the greater, for being surrounded by men carrying arms is hardly the safest place for a ruler to be. Given this social condition it is perhaps surprising that any emperor lived out a natural term. One of Diocletian’s necessary innovations, therefore, was to inhabit a palace in which physical access to him was severely restricted.

So Constantine’s claim of an hereditary right because of his invented descent from Claudius Gothicus and his actual descent from Constantius I fitted in well with the preferences of Roman society. Not only that, but his actual relationship with Maximian – he married his daughter – and his marriage alliances with other contemporary emperors eventually fitted him into the Diocletianic dynastic scheme, even while he was busy subverting it. When the Tetrarchic dynasty is examined as a whole, it becomes rather more like the confusion of the Julio-Claudian ‘dynasty’ than the straightforwardness of the Flavians.

Constantine also, of course, set up a new governing centre for the Empire, at Constantinople. Here he was again following the route blazed by several of the third-century rulers, most of whom had not been able to spend much time in Rome. Given the frontier problems they faced, the old city was an inconvenient centre for military command, though geographically sensible from a governing point of view. It also contained the awkward Senate and a city mob liable to riot, and both had supported Maxentius. The use of Milan in northern Italy and Nicomedia in North-West Asia Minor as imperial centres by Maximian and Diocletian was the first real sign, however, that a permanent shift of the imperial capital was becoming likely. The selection of Byzantium to become Constantinople was thus only the last stage in a century-long process of restless movements and temporary halts by third-century emperors. Constantine, in fact, was able to plant his new centre at Byzantium because of this work done by his immediate predecessors and enemies, just as devotion to dynastic succession picked up on a theme that has been evident all through imperial (and Roman) history. Constantinople was, perhaps, a little more convenient for some of the frontiers – though not much, and decidedly unhelpful for ruling the West – but, above all, it was not Rome.

Emperors from Alexander Severus and Maximinus Thrax onwards were clearly disenchanted with the old city, both as a governing centre and as a place with old and very powerful political and religious associations. Constantine could also claim that his new city was a Christian city from the start, which for a time made Rome a stronghold of paganism. However, detaching the imperial regime from Rome had already in effect been done by his pagan predecessors during the previous half-century, and they had often preferred other gods to those of Rome, Sol by Elagabalus and Aurelian, for example. The foundation of Constantinople was the result of casting loose from Rome, and would in all likelihood have occurred even if Constantine had never become emperor and if Christianity had never succumbed to the imperial embrace, but the actual capital might not have ended up exactly there.

One of the elements at Rome from which the emperors detached themselves by the removal of the seat of government was the Senate. It was therefore to a degree paradoxical that Constantine should establish a new Senate in his new city. Yet it was always a useful legislative and judicial body, though the very fact that it was the emperor who founded it and selected its members devalued the institution from the start. Power now resided wholly in the imperial palace, modified to some extent by the authority of bishops and holy men; and the succession, thanks to the sequence of Carus-Diocletian-Constantine, was now hereditary, leaving no role for the Senate. The imperial succession was now wholly outside the Senate’s competence.

Like his father, Constantine was twice married and had sons by both wives. He also had a considerable number of male relatives, half-brothers and their children. Daughters were married off to convenient political allies, sons were trained up as governors of parts of the Empire and, by implication, as possible political heirs. In total, when Constantine died in 337, there were three sons, three half-brothers, a grandson and four nephews (sons of his half-brothers) all available. (See Genealogical Table XVII.) In the circumstances it would have been astonishing if the succession had been achieved without a problem; in fact, it rapidly became another process of elimination by murder, another habit recalled from the imperial past.


Constantine himself had begun the process of culling and elimination. His eldest son, Crispus, had been made Caesar in 317 when he was about 16 or 17; he promised well, and in 324 proved to be an accomplished commander in the last of the civil wars against Licinius; in 326 he was executed – or murdered – by his father.3 Constantine’s three sons by his second wife were then promoted successively: Constantine II in 317, Constantius II became Caesar in 330 and Constans in 333, no doubt as each of them reached adolescence. He also promoted two of his nephews: Delmatius became Caesar in 335 and his brother Hannibalianus was ‘King of Kings’ in 337; two of his half-brothers held high posts in the administration; Delmatius (the father of the two nephews) and Julius Constantinus were respectively referred to as ‘the censor’ and ‘the patrician’. (The elder Delmatius was responsible for the suppression of an obscure rising on the island of Cyprus in 334. Its leader was Calocaerus, who ‘usurped power’; it was clearly not a serious threat, though the words used suggest that Calocaerus did attempt to make himself emperor.)4

The sons of the emperor were posted to various parts of the Empire as regional governors; his half-brothers largely remained in the capital. The provinces assigned to his relatives were changed as new members of the family grew up and were promoted. As a result, when Constantine died in 337 Constantine II was in Gaul, Constantius II in the East, and Constans in Italy; of the nephews, Delmatius was on the Danube front, and Hannibalianus had been made ‘King of Kings’ in preparation for a new Persian War, during which he was to be enthroned as king in (probably) Armenia, or even (much less probably) Persia itself.

If Constantine had designed it, he could scarcely have guaranteed more obviously that there would be a civil war and a family bloodletting following his death. Perhaps it was just as obvious at the time. When the news of his death emerged, the army in and around Constantinople staged a sort of coup, proclaimed that only the sons of the emperor should rule, and then proceeded to kill off all those collateral members of the family who were within reach.5 The result was the survival of just the three sons – Constantius, Constantine and Constans – and the two sons of Julius Constantinus ‘the Patrician’, Julian and Gallus.

Constantine’s governmental policy was reminiscent of Diocletian’s practice of assigning parts of the Empire to his colleagues, the difference being that the several rulers were of the same genetic family. The result was also the same: a war among the inheritors, with one survivor. Power is addictive, as he himself should have recalled. Constantine himself had never been content with what he had when part of the Empire was ruled by another. This attitude was inherited by his sons and nephews.

The deaths of the half-brothers Delmatius and Hannibalianus were clearly the work of the army, but Constantius II was in the city as it all happened and it seems likely that he was the organizer of the killings. He was clearly a man quite unwilling to see the Empire divided; a real chip off the old block. The three brothers met a month later at the Viminacium in Pannonia and agreed on a new division of the Empire: not long afterwards Constans and Constantine II quarrelled and the latter died in an invasion of the former’s territory.6 So from there being six emperors in 337, there were just two in 340 – Constans in the West and Constantius in the East – which was very similar to the situation between 306 and 324. Constans died in 350, killed by the followers of an enemy. Then there was just one: the family of Constantine I was reduced to a single Augustus and his two nephews, Julian and Gallus, within little more than a decade.

The Sons of Constantine


Constantine II (337–340).


Constans I (337–350).


Constantius II (337–361).

The End of Constantine’s Dynasty


Magnentius (350–353).


Julian (361–363).


Jovian (363–364).

For nearly half a century there had been no imperial rebels to threaten the dynasty of Constantine (Calocaerus excepted). Then from 350 there was a sudden rush of them, as though they sensed that they were in at the last years of the dynasty’s life and the position of emperor was once more about to become open. This might suggest that rebels tend to appear in the period when a dynasty was visibly failing, and the reduction of the family to just three members would have suggested near-failure. In fact three of the four cases of rebels between 350 and 353 are interconnected, and the fourth was an attempted restoration of the dynasty of Constantine after it had officially expired. (See Table IV.)

The first of these risings took place in Gaul. Magnentius was a high-ranking soldier of Frankish/British ancestry, popular with the soldiers. He capitalized on widespread enmity in the West towards the behaviour and policies of Constans to launch a serious and sustained bid for the Empire. At a dinner held at Augustodunum to celebrate the birthday of the son of Marcellinus, Constans’ comes rei private, Magnentius left the room briefly and then returned wearing a purple robe, at which the assembled diners hailed him as emperor.7

This was clearly a well-prepared coup. One does not have a purple imperial robe simply lying around, particularly at a time when mere possession of purple cloth by an ordinary person was considered treasonable. The diners were also no doubt well primed for the event. Constans found that his support in Gaul fell away as the news of Magnentius’ action spread. All this strongly suggests that Magnentius had prepared the ground throughout Gaul in advance. Constans fled south, to be caught and killed at a small town in the Pyrenees. Magnentius was accepted as emperor in Britain, the Germanies, Gaul, Spain and Africa, apparently with no resistance.

The sources of support for Magnentius are obvious from the account of his actions: Marcellinus was in charge of the imperial administration, Magnentius himself was in command of the legionary forces, the praetorians attached to Constans’ court were disaffected, and a unit of cavalry that was stationed near to Augustodunum at once joined the rebel. He was also acclaimed by the people of the town. This was, in all, a good facsimile of the accession of any emperor in the fourth century, perhaps better recorded by the fact of his rebellion, possibly as a result of deliberately publicizing the events in earnest of the legitimacy of his accession.

Table IV: Unsuccessful Emperors 350–425.


Magnentius was faced by rival and opposing competitors. In Pannonia an old general called Vetranio was also proclaimed emperor. This, however, was not his own idea but that of Constantia, a sister of the dead Constans and of the living Constantius II. She was apparently present at the acclamation and prodded Vetranio into action to pre-empt the further advance of Magnentius, who might have persuaded the Pannonian army to join him; with its own emperor that army was not committed to Magnentius.8 In Rome another scion of Constantine the Great, Nepotianus, led a rising that was briefly successful in seizing the city, but was soon beaten down by a detachment sent by Magnentius under Marcellinus’ command.9 Both Vetranio and Nepotianus had decked themselves out in imperial garments but both were self-proclaimed Constantian loyalists.

Magnentius attempted to bolster his position by appointing his brother Decentius as Caesar and by marrying Justina, an aristocratic girl, probably about 12 years old, whose family was part of a wide aristocratic network throughout Gaul. Even more significantly, she was the daughter of Galla, the great-niece of the great Constantine. Magnentius thus became a marital member of the imperial family, a move that might have been intended to counter the promotion of Vetranio.

Constantius II marched from Syria, where he had been fighting the Persians; a preoccupation that Marcellinus and Magnentius no doubt had in mind at the time of their proclamation. He addressed Vetranio’s soldiers, who acclaimed him, and Vetranio gracefully retired, with a pension, obviously by pre-arrangement. However, the armies of Constantius and Magnentius then met in a ferocious battle at Mursa, with both sides losing many men. Constantius was the marginal victor, then slowly hunted down Magnentius, who finally died by his own hand in Gaul in 353, his control of the West having crumbled section by section.10

Magnentius is normally, like so many others, regarded as a usurper, but also like so many others this is a judgement that results from adopting the viewpoint of his enemies. Constans had become highly unpopular in Gaul in particular, and few if any of his subjects were prepared to stand with him when he was challenged by Magnentius. Magnentius himself went through a reasonable facsimile of an imperial acclamation, not unlike that of Constantine in York or Gordian I in Thysdrus and Carthage. He was able to establish his authority very quickly over the West, and even in Italy. For three years he ruled the Western half of the Roman Empire. By all normal criteria, except that of his enemies and his defeat, he was a Roman emperor.

The other rebel of this mid-century group was Silvanus. Like Magnentius he was a soldier, of Frankish parentage. He had been a tribune in Magnentius’ army, but had changed sides just before the Battle of Mursa. For this he was rewarded with promotion to the command of an infantry force and posted the Colonia Agrippina. The historian Ammianus Marcellinus tells of a complicated intrigue in which Silvanus was a supposed innocent victim, but which resulted in his seizing power at Colonia and being proclaimed emperor.11

The story is one in which Ammianus himself was personally involved, and this has tended to distort his account, though he clearly undertook extensive researches into the preliminary intrigues. Silvanus had a good deal of local support in Germany. He had acted on impulse, it seems, feeling threatened, and he collected purple garments by stripping the purple decorations from the military standards, which could only have been done with the soldiers’ acquiescence. His seizure of power was a fairly formidable affair, perhaps fuelled by the extreme and brutal reprisals indulged in by Constantius in Gaul in the aftermath of the suppression of Magnentius. However, Silvanus’ support collapsed, as had that of Magnentius and Constans, and he was killed by men who had been lukewarm in his cause and had been persuaded to return to the side of Constantius by timely bribes.12

Silvanus’ support was very narrowly based, and his coup was clearly poorly prepared in clear contrast to the relative success of Magnentius in the same region. Both ultimately failed because Constantius II had the better army, but also because he was a ruling emperor, the son of Constantine the Great, and had been emperor already for a decade and a half. Magnentius had in fact been negotiating for recognition by Constantius for a time before the Battle of Mursa, but Constantius, once assured of the support of Vetranio’s Pannonian army, refused him. What was clearly required for success was all three elements: support from the army (which both rebels gained), general acceptance by the officials and governors (which Magnentius gained), and recognition by the senior Augustus. Only if there was no Augustus could a man make himself emperor by the support of just the army and the officials. Constantius as the direct heir to Constantine could use the crucial element of loyalty to the dynasty, but the failure of Constans was a clear sign that this was something with only a limited value.

Such loyalty was also dependent on the dynasty continuing. One of the elements in the background may well have been the likely early extermination of Constantine’s family. None of Constantine’s sons had sons of their own, though Constantius eventually had a daughter. Crispus had a son, but he was never considered; perhaps he died young. The only other members of the family were the sons of Constantine’s half-brother Delmatius, who had been killed in 337. The boys had survived because Gallus, the elder, was thought too sickly to live, and Julian is said to have aroused the pity of the soldiers designated to kill him because of his youth. Gallus was now (in 351) made Caesar and sent to the East while Constantius II coped with the rebellion of Magnentius in the West. This was in part a reassurance to the Syrians that his move to the West was not a desertion, and also a signal that the Constantinian dynasty was still active and that even if Magnentius won in the West, there were still other members of the dynasty he would have to face. However, having suppressed Magnentius, Constantius then had to deal with the misbehaviour of Gallus at Antioch. He was executed.13 The one remaining Constantinian, Julian, was then appointed as Caesar and sent to the West. Constantius was clearly unconcerned about the continuity of his dynasty.

Julian, after a successful campaign in Germany, was made Augustus by his soldiers in 360. He advanced slowly eastwards to challenge Constantius’ rule, meanwhile negotiating for acceptance. Constantius died before they could meet; Julian became sole emperor from being a condemned rebel. The difference between his and Magnentius’ conduct is invisible. He was killed in battle against the Persians in 363.14

So the family of Constantine became extinct, apart from some distant connections. This first Christian dynasty had behaved in the same way as its non-Christian predecessors: it had not only failed to reproduce itself, but its members, particularly Constantius, had then compounded that failure by all too readily resorting to killing other members. There was just one survivor, the daughter of Constantius II, Constantia Postuma; the dynasty had in effect expired.

On the other hand, this was the first dynasty whose rule in the Empire had lasted more than half a century since the death of Nero (discounting the second-century rulers as a non-dynasty). Counting from the promotion of Constantius I as Caesar in 293, the family had ruled for seventy years and had lasted through three generations. (The fiction of the descent of the family from Claudius Gothicus could be said to have extended this to ninety-five years and five generations.) Constantine’s dynastic programme, if it may be called that, had certainly replaced Diocletian’s curious scheme and he had re-established dynastic inheritance as the appropriate method of delivering the succession in the Empire. Constantine had not actually solved the real problem, which was that no Roman imperial dynasty, except the first (if the Julio-Claudians may be counted as a single dynasty) had lasted into the fourth generation. He had made an attempt to train up his sons, but was then partly foiled by the army he had also trained, and by the mutual suspicions and ambitions of those very sons, who feared each other as much as any outsider.

The hereditary principle that Constantine had been at such pains to implant could only survive if there were dynastic members available; it also required a certain trust between the several members. Failing those qualities, the problem of choosing a successor devolved elsewhere. The army Julian was commanding at the time of his death was deep in Persian territory and under imminent danger of attack. The problem of the imperial succession therefore automatically devolved once again on to the army which required a new commander who must be an emperor. So once more the method of choosing a successor was to be decided in an emergency situation, the previous emperor having been deficient in his duty either to father an heir (Julian’s only son had died the year before) or to nominate a successor.

Finding a successor for Julian was the subject of extended discussion. For once we have a detailed description of what happened. A council of army commanders met in order to choose the successor. Ammianus Marcellinus, who was with the army at the time and may even have attended the council itself, recorded an account.

The men at the council were the legionary commanders, the commanders of the cavalry squadrons and a number of court and administrative officials who were also present with the army. This must have made for a fairly numerous gathering. There were two groups with definite ideas as to whom to choose and a considerable number without a programme at all. One group wished to choose a man from among Constantius’ palace officials, that is, a bureaucrat; the other group wished for a soldier. It was much the same division as had been visible when Macrinus killed Caracalla, and similar in a way to the parties that had followed Maximinus and the Gordians through the third-century crises, or as personified in the confrontation between Diocletian and Aper, and even further back the decision required by the army commanders in Pannonia when the news of Nerva’s accession reached them. In this case, curiously, each group cancelled out the other and a compromise candidate was agreed on: Salutius Secundus, the Praetorian Prefect.

However, Salutius then refused and persisted in his refusal even when one of the soldiers suggested that he take command only until the army had been conducted to safety. The Praetorian Prefect by this time was an administrator and legal expert rather than a soldier, so it looks as though the ‘compromise’ came down on the side of the Palace officials. Salutius, of course, as the prefect, was the senior man in the camp, more senior than any of the military men. It also looks as though the soldiers’ suggestion of a temporary command was sarcastic, made in order to persuade Salutius to refuse. His refusal now left the way open to the ordinary soldiers, who were impatient at the long delay by their superiors and who now put forward Jovian, the commander of the household troops, as their candidate. He was young, fairly junior, but to have reached the position he held at his age he was clearly a coming man. He also had a young son.15

Jovian was acceptable to the Palace party perhaps because of his youth and comparative lack of experience, and to the senior officers because he was a soldier. He was, that is to say, another compromise candidate, just as Salutius had been. He was successful in extricating the army from its difficult position and in making peace with the Persians. Then he died in some mysterious way – supposedly suffocated by the fumes from a stove – during the march towards Constantinople, having reigned for only a few months.

The army officers’ council met again at Nikaia, across the Propontis from Constantinople. Salutius was again suggested as emperor and again refused. Others were then considered. One was Aequitius, commander of the targeteers’ regiment; another was Januarius, a relative of Jovian, also an official. Both were rejected for odd reasons: Aequitius because of his boorishness; Januarius because he was too far away. This seems an unlikely reason, for the man who was actually chosen was in Ankyra at the time, far enough off in all conscience. It looks like a discussion in which each candidate who was put forward was vetoed by the rest. (The details of the meeting are much less clear than that in which Jovian was chosen; Ammianus was not present this time.)

In the end, and yet again, a man below the top ranks was chosen. It seems evident that the senior officers could not agree on one of their own number, perhaps because all of them wanted the job, and so all combined to deny it to anyone else. This time the choice fell on a man called Valentinian, who was of a higher rank than Jovian had been and at 43 was somewhat older. He was an active and moderately well-known officer, who had been involved in the suppression of Silvanus’ rising in Gaul a decade earlier. He was summoned from Ankyra – two or three days’ ride away – and then at Nikaia he took a day or so to think about it (using the excuse that it was an unlucky day in the Roman calendar). It was clearly possible for him to refuse, as Salutius had shown. The senior officers meanwhile found it difficult to control the army, and when Valentinian was presented to the rank-and-file, they began to demand the appointment of a second emperor as his colleague.

This made sense, since the destruction of the dynasty of Constantine and the deaths of three emperors in the last three years had demonstrated the awkwardness of the method being used. It had also become customary, for at least the last century, to have a second man invested with the post of either Caesar or Augustus who could take over at once when one emperor died. The soldiers’ demand was therefore sensible and Valentinian heeded it, though not immediately. He was advised to choose someone not of his family, but since that advice came from one of the disappointed generals, it was scarcely disinterested and was possibly a bid for the post that he had already implicitly been refused in the conclave. None of the obvious candidates who had been at the council could be chosen, for this would immediately annoy all the rest and cast doubt on the validity of his own selection. Valentinian met with his younger brother Valens as soon as possible and installed him as joint Augustus. It was only close relations who could be trusted and even then not always, as the debacle of the Constantinian family had shown.16

This choice of an emperor was clearly a fairly orderly process. It also took some time, for the ordinary soldiers became impatient, specifically at the delay; if a candidate had been agreed quickly, the soldiers would clearly have accepted him and it was Salutius’ obstinate refusal to take the post that caused the delay. There was obviously a considerable degree of discussion involved and a wide variety of candidates were considered once Salutius refused, perhaps even before. There is no doubt that several men in the council hoped to be chosen; the putting oneself forward was evidently not acceptable. It is obvious also that once a decision had been made they generally fell in line and accepted the chosen man.

The range of candidates would appear to be fairly wide, and included the senior men of the army and the court administration and army officers down to Jovian’s rank, which was the equivalent of a modern regimental colonel. It was also possible for a man to refuse without incurring danger to himself. Salutius continued working for both Jovian and Valentinian.

How far this council was typical of early and similar crises is difficult to say. Earlier cases of emperors dying on campaign were usually the result of murder (Caracalla, for instance) – Gordian III and Numerian may have suffered more natural deaths – or there was an obvious candidate in office or nearby (Valerian, Trajan and Philip the Arab). Further, it was a long time since a similar situation had arisen. The councils periodically convened by Diocletian were the obvious precedent rather than the swift and pre-arranged elevation of Constantine. It seems probable, therefore, that the councils in 363 and 364 occurred because no immediate or obvious successor existed. Probably Salutius was the convener of the council and the dominant member; in that case one can see the logic of the council’s original choice.

The participation of the ordinary soldiers, in putting Jovian forward and then insisting on the appointment of a joint emperor, is notable. No doubt Jovian was acceptable to the senior officers, and the soldiers’ initiative might well have been cleared with them first; a second emperor was clearly a good idea, so men and officers could be seen to have been thinking along the same lines.

The whole process of selection in this case has the appearance of a distorted version of an old Roman election, with the candidates being discussed in a council of magnates (a pseudo-Senate), and the decisions made there being subject to popular acceptance (a pseudo-Assembly or comitia). What is actually very clear is that neither the Senate (that in Rome or that in Constantinople) had any input, nor was even considered. Nor, of course, were the generality of Roman citizens considered or consulted, but that was scarcely new.

Jovian had made a start at founding a dynasty when he appointed his infant son as consul. Appointing a grown brother, as Valentinian did, made rather more political and military sense, and the two brothers worked well together; or rather separately, for they tended to operate at opposite ends of the Empire. Valentinian had an adolescent son and Valens soon had an infant son, which seemed to take care for the moment of their heredity and were the foundation for a new dynasty.


Valentinian at some point divorced his first wife and married Justina, the widow of the usurper Magnentius and the grand-niece of Constantine I. She was married to Valentinian in 371, having been a widow for eighteen years, though it seems that her liaison with the emperor had begun rather earlier. They had three daughters and a son; thus the new dynasty was joined to that of Constantine. (For the connections so formed, see Genealogical Table XVIII.)

This marriage, with its retrospective connections to the previous dynasty, was similar in its effects to Constantine I’s claim to be the descendant of Claudius Gothicus; or perhaps a better comparison is with Septimius’ retrospective self-adoption into the Antonine family. In the same way Valentinian’s eldest son Gratian was married to Constantina Postuma, the daughter of Constantius II, and then to Laeta, another sprig of the old imperial nobility in the West. These political marriages indicate the continuing importance of the Western nobility, particularly in Italy and Gaul, but also the need for the new imperial family to acquire some of the lustre of the family of Constantine. This was all typical marital behaviour of any dynasty, of course, royal or otherwise.

The need for such support had become clear soon after the new family had acceded to the throne. In 365, only a year after their elevation, the Emperor Julian’s cousin Procopius seized control of Constantinople, claimed the throne and emphasized as strongly as he could his relationship with the dynasty of Constantine. This connection was, it has to be admitted, rather distant; he was the son of Julian’s mother’s sister, thus his first cousin, but on the female side. It was perhaps no more distant a relationship than some of those among the family of Augustus, or in that of the later Severans, though normally a clear blood connection was expected. It was the same sort of relationship that was provided to Magnentius by his marriage to Justina and it was potent enough for Valentinian I and Gratian to repeat it by their own marriages. Yet such a relationship is only, as it were, enabling; to make it effective, the claimant had to show ability as well. What Procopius’ attempt reveals is the strength of the dynastic impulse that had now developed. Also, if such a distant connection was accepted as legitimate, it would open the gate wide to the many other claims.

Procopius was acceptable in part because of his culture and sophistication, particularly to the city’s elite, but this cut no ice with the army, at whom the family connection with Constantine was clearly aimed. Valentinian had moved off to the Western provinces by the time Procopius emerged and Valens took his time to deal with the problem, spending the winter of 365–366 watching, waiting and gathering support. He was so successful that Procopius’ support gradually crumbled. He finally marched against Valens, rather desperately, but one of his generals switched sides during the fighting and the revolt was over. Procopius fled but was soon captured and executed. A relative of his, Martialis, ‘seized the shadow of a failing principate’, as Ammianus puts it, at Nikaia, but after a fairly short time he was seized by some soldiers sent by Aequitius, scourged and executed. His claim to the throne depended on his relationship with Procopius, who claimed it by a supposed but remote relationship to Julian. Only Procopius had any success, largely perhaps because he claimed that Julian had secretly made him his designated successor. The story was thin to the point of transparency, but the lesson was clearly not lost on Valentinian at least, whose first moves to gather Western aristocratic support came in the year after Procopius’ collapse with the marriage of his son Gratian to the daughter of Constantius II.17

Procopius and Martialis had tried to claim the throne by right as members of the royal family. The other rebellion against Valentinian and Valens was rather different. An internal tribal dispute in Roman Mauretania pushed Firmus, a claimant to the local kingship of his father, into rebellion. Valentinian I sent his general Count Theodosius to suppress it, which he did over a period of two years or so, campaigning in the very difficult terrain of the Atlas Mountains. Theodosius had successfully recovered control of Britain in 367 after a series of barbarian invasions. Firmus’ support steadily dropped away, and finally he came out dressed in a purple cloak, exhorting his enemies to rebel against Theodosius, whose discipline he derided. When this did not work, Firmus committed suicide.18 (For these pretenders and rebels, see Table IV.)

As an imperial pretender Firmus was clearly a non-starter: his aim was always to achieve his father’s local position, though he was also capable of exploiting local grievances such as the perennial complaints about taxation. His final actions are reminiscent of the last desperate measure used by Gallienus’ general Aureolus, who also came out in a purple cloak as his rebellion was failing, or of the bacaudae leaders fighting Maximian. These men clearly over-estimated the effect they expected to have, but it is at the same time a mark of the power of the purple cloak; for it to be over-estimated, an effect has already to exist.19

The fourth century, therefore, witnessed true dynastic succession in the Roman Empire for the first time since the brief Flavian dynasty in the first century and perhaps the Severans, and when the direct Constantinian line finally died out with Julian, a new dynasty was soon in place, which, though it tended to break up towards the end, and though it needed an infusion of reinforcement, lasted even longer. One factor in its relative success was the Valentinian dynasty’s marriage connection back to the family of Constantine. (See Genealogical Tables XVIII and XIX.) These, and the appeal made by Procopius, are testimonies to the continued reputation of Constantine and his family.

Paradoxically, of course, the emergence of two successful and successive dynasties raised the stakes of power even higher, for if a man could become emperor he now stood a much better chance than ever of founding a dynasty. The intentions of Augustus had finally been realized. This development had been in question all through the history of the imperial system. Its final emergence added one more element to the succession system. Now there was a perception that the succession would go normally to a member of the imperial family, if a close relative of the former emperor existed. Both the army and the Senate had been effectively removed from the process.

The House of Valentinian


Valentinian I (364–375).


Valens (364–378).


Gratian (375–383). (Sjuergen via Wikimedia Commons)


Valentinian II (375–392).

The House of Theodosius


Theodosius I (379–395). (Marie-Lan Nguyen/Wikimedia Commons)


Arcadius (395–408). (Gryffindor via Wikimedia Commons)


Honorius (395–423).

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