Ancient History & Civilisation

Chapter Fifteen

The Crises of 375–379

The dynasty founded by Valentinian in 364 consisted of the two brothers plus Valentinian’s children; Valens’ son died young and he had no other offspring, it seems. When both emperors died within four years (in 375 and 378), therefore, the dynastic crisis developed into an imperial one.

Valentinian died first, suffering a stroke when he became angry at the unhelpful and insulting answers of a barbarian embassy. He died shortly after the stroke. In the interval he had been unable to communicate with his entourage and could not give any instructions about the succession,1 though these were not really needed. His brother automatically became the senior emperor and Valentinian’s eldest son, Gratian, had been raised to the rank of Augustus in 367 when he was only 8; there were therefore still two emperors, one in the West and one in the East.

The 16-year-old Gratian was just about old enough to be seen as a legitimate and ruling emperor, and he could be regarded as under the distant guardianship of his uncle, Valens. The brothers had taken responsibility for the Western and Eastern parts of the Empire respectively, and Valentinian died at Brigetio on the Danube, while Valens had been in charge in the East from the start, being based at Constantinople, though at the time of Valentinian’s death he was actually in Antioch. Gratian was at Augusta Treverorum (Trier) on the Rhine frontier. This geographical separation is crucial to what happened next, for neither of the emperors could bring any pressure to bear on the entourage of Valentinian at Brigetio, which amounted to the main central government authority of the West, overriding Gratian at Trier because of his youth.

Neither Valentinian’s son nor his brother could reach Brigetio in less than two or three weeks. Valens was clearly too busy and too distant to attend a face-to-face discussion on the succession, and Gratian was still too young to be heard. Valentinian had been in the midst of negotiations to try to bring an end to the war with the Quadi when he died, and that war was still being fought. It was clearly necessary to be able to conduct the war or negotiations in Pannonia, and only an emperor who was based on the Danube frontier had the necessary authority to do so.

To the men at Valentinian’s court it must have seemed urgent to have an emperor in whose name they could carry on the war and the government. Yet there were already two Augusti, and Gratian had clearly been intended to be Valentinian’s direct successor; Valens was now the senior of the two, but there was clearly more than this dynastic matter involved in the situation. These quasi-altruistic factors do not, of course, exclude elements of personal ambition among the courtiers at Brigetio; indeed, it may well be that these were actually paramount.

The central figures were ambitious enough. The main engine of events following the emperor’s death was Sextus Claudius Petronius Probus of a senatorial family who had, unusually for a man from such a family, made a successful high-flying career in the imperial administration. He was accompanied by Flavius Aequitius, an early supporter of Valentinian’s (and a participant in the succession discussions after Julian’s death). He had been regarded as a candidate for the throne in 364 at the conclave at Nikaia and had been instrumental in extinguishing the last embers of Procopius’ usurpation the following year. Two prominent soldiers were the magister militum Flavius Merobaudes and Sebastianus, both out on campaign at the time; there was also Count Theodosius, at that moment just completing his campaign in Africa against the rebel-pretender Firmus. These, as will be clear, were no band of brothers, and it is an indication of Valentinian’s power of command that he was able to harness this disparate group into working together.

The men at Brigetio – probably, in fact, Petronius Probus – sent a message to Merobaudes, who was beyond the Danube with the army in enemy territory. The message was in Valentinian’s name, though it was sent after his death. Merobaudes was apparently told that the emperor was dead, presumably either by another letter or by word of mouth from the messenger. His first action, before turning back, was to despatch his fellow general Sebastianus far away. Then he returned to the court, which had moved on to Aquincum. Sebastianus was popular with the soldiers, and was therefore seen by Merobaudes as a danger; Merobaudes was thus preparing the ground for an action that would set him against both Sebastianus and possibly the troops as well. That is, neither Merobaudes nor Sebastianus, nor the men in the court at Aquincum, had any intention of simply acknowledging Gratian’s and Valens’ authority.

The senior man at Aquincum, Petronius Probus, was Praetorian Prefect of Illyricum and Italy, and it is presumably an alliance of Probus and Merobaudes which was the engine that drove events, though the officers with Probus acted before Merobaudes arrived, even if they clearly assumed his agreement. By the time he got back to the court, the plan had been made and put into effect. There was, living near to Carnuntum at an imperial estate called Murocincta (probably the modern Parndoff), Valentinian’s other son, also Valentinian, with his mother Justina. Her brother, Cerealis, was with the court. He was sent to her and she and the boy were brought the 100 miles to Aquincum. There the boy was hailed as Augustus.

The proclamation took place on the sixth day after Valentinian I’s death. The decision to send for the boy was thus taken very quickly, even before Merobaudes got back to the court, for Cerealis had to travel the 100 miles twice, making the return journey with Justina and the boy in a litter and so fairly slowly. Six days was therefore extremely good going, and suggests that these events had been set in train before Valentinian died, while he had been comatose. It follows that the real decider in all this was Petronius Probus, with the others going along.2

Some of the others at the court at Aquincum will certainly have pointed out that Gratian would have good cause for annoyance at these events, but it would be clear to all that he could do little about it since the court on the Danube commanded the major part of the Western army. By the time Gratian heard of it, the new regime would be well-established. Probus, as Praetorian Prefect for Italy and Illyricum, give it a flying territorial start.

This procedure is very reminiscent of that by which Valentinian himself had been made emperor. It was, of course, a coup d’état, and if Gratian had objected, Valentinian II would have been labelled a usurper and a civil war might have followed. Valens might also have objected, but he was fully involved in the East and then from 376 he was heavily preoccupied with the Gothic problem on the Danube frontier. As it was, Gratian, or his handlers, did not object and instead, showing the good sense that marked him out, took his half-brother and his stepmother into his own court at Trier.3 He thereupon effectively nullified the Brigetio coup and acquired control of the new emperor, who could thus be seen as the heir of his own throne but this was at a cost.

The years 376 to 378 were those that led up to the Battle of Adrianople, in which Valens was killed. In the West it was a time of murderous intrigue in the joint court of Gratian and Valentinian II. One outcome was the killing of Count Theodosius who had just succeeded in suppressing the awkward rebellion of Firmus in Africa. It would seem that Theodosius was thought to be a likely enemy of those in control in the Western part of the Empire in the same way that Sebastianus had been feared by Merobaudes and perhaps by Petronius Probus as well.4 His son, also Theodosius, quickly retired to his northern Spanish estates, got married and settled down; similarly Sebastianus was in retirement in Italy when Valens asked for his services a little later in the Gothic war. The elevation of Valentinian II was thus part of a long-running faction dispute within the court of Valentinian I, which came to the surface when he died and which Gratian, by uniting the two Western courts, had imported into his own entourage. He was clearly not immediately able to control the conflict.

The intrigues of 375–376 against Theodosius in particular, however, rebounded: those factions that compassed his death were themselves soon removed. The younger Theodosius was recalled in (probably) 377, just about the same time that Sebastianus returned to favour and authority with Valens in the East.5 When Valens died, therefore, in the battle at Adrianople, leaving a chaotic situation in the Balkans, there was an immediate need for a new commander there. Sebastianus would have been the obvious choice, but he had been killed in the battle alongside the emperor. Gratian had been on his way to help Valens when the battle took place, and had to retire to Sirmium in the face of the chaos. The Gothic forces threatened Constantinople, and the whole of the Balkan Peninsula dropped out of the control of any Roman government.

By means of a timely minor victory, apparently against some Sarmatians and so somewhere along the lower Danube, the younger Theodosius came to the notice of Gratian at Sirmium. This brought him promotion, and now he was suggested as the right man for the job of restoring order in the East. No doubt Theodosius agreed with this assessment, but it was not until January of 379, more than five months after the Battle of Adrianople, that he was finally appointed.6 He had been with the court all that time, clearly available, and the need had been as urgent in September as it was in January. The delay has to be explained.

The answer appears to be that Theodosius insisted that he must be appointed emperor, not just general. (This was sensible of him, for his military ability was only adequate; he would be much more effective as emperor than in direct command of the army.) He already had a number of relatives in prominent positions at Gratian’s court: his uncle Flavius Eucherius was comes sacrarum largitionem, and an in-law, Flavius Claudius Antonius, was Praetorian Prefect for Gaul and was then transferred to Italy; Petronius Probus seems to have been a supporter as well, if not an actual relative. All these men would also have had their own men in posts around and beneath them, forming a set of factions that had now coalesced around Theodosius.

Theodosius’ insistence on being promoted to emperor, not just magister militum or something similar, presumably derived from his father’s experience. The older Theodosius had been sent to put down trouble in Africa, just as the younger was being proposed as the man to do that in the Balkans. Having succeeded, he was then arrested and executed in an intrigue of his enemies at court, and some of those enemies were still present (not to mention that the brother of Firmus, his father’s enemy in Africa, was still in authority there as governor). This had happened only two years before. The younger man’s demand for an authority that would put him out of reach of the court intrigues at Gratian’s court and of the knives of vengeance-seeking Africans – and perhaps with the power to wreak his own revenge – is thus quite understandable, though it may well have startled, even dismayed, his political allies, just as it apparently took Gratian aback.

It therefore took several months to convince Gratian, now the senior Augustus, both that another Augustus was needed in the East, and that neither he nor Valentinian II (still only 8 years old) was suitable or available. Gratian at this time had to stand guard in the West, where he had recently attacked and defeated the Alamanni. Finally, he had to be convinced that Theodosius was the right man to be the new Augustus. It clearly required a man with military skills and Theodosius’ past victories (and those of his father) suggested that he had them. Nevertheless, Gratian was clearly difficult to convince, though in January he was finally persuaded and Theodosius was installed as emperor.

For the second time in three years, an emperor had died in circumstances that made it impossible for him to appoint an immediate successor. In each case the officials of the court in attendance had put forward their own candidate, and Gratian, senior emperor once Valens was killed, was then constrained to accept him. In both cases the procedure was in fact close to being an internal coup by the court officials and the senior commanders.

The similarities of these intrigues to the choice of Jovian and then of Valentinian I only a decade and a half earlier are clear: the discussions between the army chiefs and the senior civilian officials; their promotion of fairly unlikely candidates (a 4-year-old child and the son of a disgraced general!). In addition, there was the need to either intimidate or persuade the reigning emperor or emperors. Gratian made no objection, it seems, to the promotion of Valentinian II, even though it was done without his authority and clearly with the interests of his backers more to the fore than those of the Empire. By annexing the child, however, he could put himself in a position of control, but it took a long time to get him to accept Theodosius who, of course, could not be dominated. There was no involvement of either the ordinary soldiers or the Senate in any of this, though the soldiers had had some influence in the elevation of Valentinian and Valens.

The promotion of Theodosius, in particular, has resonances from earlier imperial crises: the promotion of Trajan in the face of Nerva’s reluctance is one parallel, involving as it does an ongoing war in both cases. It also has references to the Antoninus adoption process at the end of Hadrian’s reign, though by this time multiple emperors were normal and actual adoption was not deemed necessary as well as being unseemly, for Theodosius was a good deal older than Gratian. However, the real precedent in the 370s was the elevation of Constantine I in 306 by a court group associated with his deceased father. The promotion of all the emperors from Constantine to Theodosius was the work of similar groups of courtiers and soldiers, and in all cases their candidate was initially unacceptable to the existing emperors, or was a child.

The real innovation in 379, however, was that Theodosius had no obvious connections with the ruling house other than as an official. As an adult with children he was clearly setting himself up as the head of a new dynasty competing with, or perhaps, more politely, complementing the dynasty of Valentinian. It was above all in this that the events of 378–379 constituted a coup d’état. As it happened, Theodosius did succeed in establishing his family as a ruling dynasty, but only after something of a struggle. His example was scarcely encouraging for the stability of the Empire, where a general could muscle his way to the emperorship using a minor victory and a crisis as his credentials.

Enemies of the House of Theodosius


Magnus Maximus (in the West 383–388).


Eugenius (in Italy 392–394).


Johannes (in Italy 423–425).

The Later Theodosians


Constantine III (407–411).


Theodosius II (408–450).


Constantius III (421).


Galla Placidia. (CNG Coins via Wikimedia Commons)

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