Chapter Six

The Consequences of Trajan: The Antonine ‘Dynasty’

Trajan spent his reign in and out of Rome, fighting wars, collecting glory, and paid no heed to the nomination of a successor. This, given the circumstances of his own nomination, seems reprehensible. Alternatively, it may have been a matter of self-preservation, since an eager heir was dangerous. Rather as with Tiberius’ and Titus’ successors, this attitude was partly because his successor was generally assumed to be Hadrian, who was his distant cousin and also his nearest male relative. It may also have been in part a recognition of the necessary role of the Senate in the emergence of a successor. (See Genealogical Table VIII.)


Since Trajan became sole emperor, Hadrian had been closely associated with him; he had brought the news of Nerva’s death to Trajan at Colonia Agrippina in early 98; he had married Trajan’s grand-niece, Sabina (she was thus also his own cousin); he had been pushed through the sequence of magistracies at Rome as swiftly as possible, though without too much acceleration; he became consul in 108, only just under the legal age for patricians. He had been military tribune in three legions and had commanded a legion; he had governed two major frontier provinces: Pannonia and Syria. There could be no serious doubt that Hadrian was intended by Trajan to be his successor, if anyone was, and that he had been well-trained for the role. Yet the preference Hadrian had been given had not been particularly obvious; no formal statement had been made of his selection, nor had he been invested with the necessary imperial powers.1

It was thus something like the situation of Domitian during Titus’ reign in that he was assumed to be, but not publicly acknowledged as, the emperor’s successor. In the event, the situation differed in that Domitian was with Titus when he died, not far from Rome, and so could present himself at the Senate right away. No record actually says this, but Domitian was probably voted the imperial powers the day after Titus’ death, so he was presumably present. The absence of comment rather implies that everything went smoothly; in particular we might assume that Suetonius, who did not like Domitian, would have commented if something had been untoward or had gone wrong. There were certainly adverse comments on Hadrian’s actions when Trajan died, but these can in part be put down to Trajan’s carelessness in dying where and when he did and in not naming Hadrian specifically as his successor. The real cause of the new procedure was Trajan’s coup against Nerva in 97, which outlined a new method of succession.

When Trajan died, he was on campaign, or rather he was returning from yet another attempt at conquest. He had suffered a stroke in the spring of 117 while he was at Antioch, and he set out to return to Rome soon after, travelling by sea, intending to celebrate yet another triumph. He was taken seriously ill in August in Cilicia, at the small town of Selinos, dying on the 11th. It is the remoteness and isolation of his death which is at the root of subsequent controversies. He seems to have been unable to communicate, and his wife Pompeia Plotina took over his correspondence. In particular, she wrote to Hadrian, who was now governor of Syria and in command of the Parthian War which was going badly. The day after Trajan died, Hadrian, at Antioch in Syria, had himself proclaimed emperor. He had received a letter, supposedly from Trajan, a couple of days earlier, officially adopting him as Trajan’s son. Having administered the oath of allegiance to the troops under his immediate command – that is, the garrison of Syria and the whole of the expeditionary force with which Trajan had been trying to conquer Mesopotamia and so a large proportion of the whole imperial army – Hadrian wrote to the Senate describing what had occurred.2

There has always been a whiff of conspiracy about this sequence of events. Any sudden death of a ruler in the ancient world brought rumours and accusations of poisoning and this was no exception. In fact Trajan’s earlier stroke and a list of his physical ailments makes it clear that his body was breaking down. Plotina signed the official documents at this time in Trajan’s name, and there were rumours linking her with Hadrian in an unlikely amorous affair. The fact that Trajan had named no successor publicly was also the subject of rumour, to the effect that he had already favoured someone other than Hadrian. The one nugget of truth in all this was that it was Plotina who sent the news to Hadrian of Trajan’s sudden illness, of his adoption, and his subsequent death. All this may well have been the doing of either Trajan or Plotina, or by Plotina in Trajan’s name (the most likely alternative), or both together, possibly planned and arranged well in advance. She was abetted in this coup by the Prefect of the Guard, P. Acilius Attianus, who was also an old colleague of Hadrian’s, which produced yet more suspicions.

One of the stories that circulated was that Trajan had not named a successor because he respected the constitutional principle that it was the Senate’s prerogative to choose a new emperor. This is an anti-Hadrian interpretation, reflecting the fuss that Helvidius Crispus had made at the time that Vespasian wanted Titus to be named as successor. The Senate had only once ever named a new emperor, Claudius, and even then it had been prompted to do so by the Guard. (Nerva had been presented as already installed.) In fact, the naming of a successor by the reigning emperor was by this time a prerogative of the emperor and had been so for almost a century and a half, ever since Augustus’ long search for one. Furthermore, the political and military situation in the East in August 117 was such that it was not possible to wait for the Senate to invest a successor. The Empire was at war, and the largest section of the army was concentrated in Syria and actually under Hadrian’s command by delegation from Trajan. It would take several weeks at least for word to get Rome, for the Senate to debate, and for the chosen successor (if it was not to be Hadrian) to get to the army; in the meantime it would be quite possible for new candidates to emerge, with the attendant risk of civil war. In practical terms it was essential that the army be under imperial command and that meant installing Hadrian as emperor there and then.

For it has to be emphasized that the army was the emperor’s, not the Senate’s, and any attempt by the Senate to interfere in army commands was met by an instant and decisively negative imperial response. Also, since it was the emperor’s army, a period without an emperor meant that the army was out of control, for the officers had no commissions that were valid and the soldiers were free of their oaths. To object that Hadrian should have awaited the Senate’s decision on the succession is to ignore that basic fact.

Then there was the other ‘constitutional practice’ involved, dating from Trajan’s nomination: the cabal of the senior generals. It was those men who had chosen Trajan, who had thus been imposed on both the Emperor Nerva and the Senate. Hadrian was in a similar situation, for a similar group of high commanders was gathered in Syria where Trajan had gathered nine full legions, together with vexillations of eight more, for the Parthian campaign. This was equivalent to the force collected for the Northern War in 96–98, and it was to these men that Hadrian immediately turned when he knew of Trajan’s death or near death. His first act was to administer the oath of allegiance to the army, which implies that he was acceptable to the men on the spot, and in particular to the senior officers, who would take the oath personally in Hadrian’s presence and who would then go on to administer the oath to their legionaries. (He also quickly withdrew from the war, with little military complaint; perhaps this was something he promised to do.)

Needless to say, the Senate did not like this procedure. Selective senatorial memories would emphasize the accession of Nerva, when the Senate had been consulted, but not that of Trajan, which was the precedent Hadrian was following. It is from senatorial circles that many of the rumours about Trajan’s death and questions about Hadrian’s accession emanated, all designed to discredit Hadrian. It was certainly the case that the Senate had been sidelined, even ignored. It was only after having been proclaimed emperor, having been acclaimed as such by the army in the East and having taken the oath of allegiance from the army, that Hadrian had sent word of his accession to the Senate. Like Trajan, he was the army’s candidate.

In his letter Hadrian paid lip service to the Senate’s authority in the matter, blaming an over-hasty salutation by the soldiers for his assumption of power.3 However, he did no more than this, and he had already exercised his imperial authority in replacing the governor of Judaea and ordering the evacuation of the areas of the Parthian Empire that were still under Roman occupation. When he set out to march west, he appointed a new governor of Syria to replace himself. All these were imperial decisions, accomplished well before he had any response from the Senate.

The Senate actually responded with extravagant praise for Trajan, who was deified unanimously, something that Hadrian had requested in his letter, but the Senate also added ‘many things in his honour which Hadrian had not requested’.4 Hadrian’s withdrawal from the Eastern conquests, and from parts of Dacia that had also been conquered by Trajan, was not popular in Rome, and the great praise the Senate bestowed on Trajan’s memory was in some sense a senatorial snub to the new ruler. It was also in a way an insult that he was offered the triumph to which Trajan had been entitled, and which the deceased emperor had been intending to enjoy once he had reached the city. Yet the imperial powers could not be denied to Hadrian, and were perforce awarded in formal terms. It was perhaps in reaction to the Senate’s coolness that Hadrian deliberately cultivated his image as a quiet, civilized gentleman, and that he spent so much of his reign on his empire-wide travels.

Hadrian had in fact followed the precedent set by Trajan: first, a late adoption by the reigning emperor, then an acceptance by the army, and only then a reference to the Senate and the voting to him of the imperial powers. The Senate’s annoyance was therefore the result of Trajan’s dying outside Rome, where the Senate could not take part in the process except retrospectively. There is no sign that if Trajan had died in the city, accession would have been any different. Trajan’s accession had been an army coup, an expression of military annoyance at the murder of Domitian, an expression of no confidence in Nerva, but above all a deliberate removal of the Senate – from whose ranks Nerva had emerged – from the decision-making process. In a way the Senate had only itself to blame for having accepted in Nerva such an obviously civilian figurehead, ignoring the fact that the emperor’s basis of authority had always been the army, which required to be commanded by a man of some stature and experience in military matters. The rebellions against Nero had also been in favour of better commanders: Galba, Verginius Rufus, Vespasian, even Vitellius.

Despite the involvement of the generals, and hence the army, in the selection of Trajan in 97, it was the ruling emperor who had emerged as the determining element in the succession. The actual moment of appointment came when Nerva announced his adoption of Trajan in Rome just as the letter announcing Trajan’s adoption of Hadrian was the moment when the succession in 117 was decided. The Senate had not been involved in Trajan’s ‘emergence’ – Nerva had merely announced Trajan’s appointment – though it soon awarded him the necessary imperial powers, nor was it involved in Hadrian’s accession. This was the essential result of the crisis of 96–97; the sidelining of the Senate and the powers of imperial succession were now firmly in the hands of the emperor and the army. This was the result of the senatorial coup in 96: the generals were reacting against what appeared to be a reassertion of the Senate’s authority.

It may be argued that this had been the case earlier, in particular under the Flavians, but the Flavian succession had in effect been determined by the Senate in 70 when the emperor’s sons were fast-tracked along the route of elective offices. This was partly the result of Vespasian’s victory in the civil war, but also because, for once, the emperor had adult sons. Now, once more, emperors were childless. Under the Julio-Claudians this gave the Senate the power of appointment as with Gaius and Nero, but above all with Claudius. The childlessness of Nerva and Trajan should have brought the Senate back into the game but it did not; that power instead gravitated back to the emperor, and there it stayed. The return of the Senate to the centre of the selection process in 96 had been so botched – Nerva was as poor a choice as Vitellius, Nero or Gaius, if in different ways – that the power of imperial confirmation had been taken from it. Trajan in many ways was a revival of Domitian, in policy, in age and in capacity.

It may have been the military situation that weighed most heavily with the Senate in deciding its response to Hadrian’s coup. Trouble had erupted in Britain, in Mauretania, in Dacia, in Egypt and in Palestine even before Trajan was dead, and the new emperor had to spend much of his first year in power attending to the most dangerous of these problems, along the Danube. It was all in addition to the Parthian War, which Hadrian at once closed down; in all, a clear demonstration of the need for a military commander to take charge, and in the circumstances that could only be Hadrian.

The discontent in the Senate, however, clearly reached Hadrian, and this must be the basic cause of the murders of four extremely prominent men who were killed during Hadrian’s first year, before he even reached Rome. They were A. Cornelius Palma, twice consul, one of Trajan’s better generals and conqueror of the Arabian province; L. Publilius Celsus, twice consul; Lucius Quietus, the deposed governor of Judaea who came from Mauretania and may have been involved in the revolt there; and C. Avidius Nigrinus, who was accused of having plotted the murder of Hadrian. The personal and political connections between these four men were no more than tenuous; their real connection is their earlier enmity towards Hadrian, together with the senatorial discontent, which could have provided the political setting and background for a coup. They were all also, sometimes explicitly, seen as possible successors to Trajan during his lifetime and so alternatives to Hadrian, just the sort of men who could have been put forward by factions of the army in any gap between emperors, the gap Hadrian had foreclosed by his instant assumption of power in Syria. A coup in favour of any of them would now, of course, necessarily have required the killing of Hadrian as a first step; this was the lesson of Domitian, Nero and Gaius. If a coup was planned, these distinguished men were exactly the group who needed to be recruited to head it, just as Nerva, twice consul, had headed a high-level group of consulars to remove Domitian. They could then turn to the Senate and exert their accumulated authority towards whoever was to be the new emperor; Avidius Nigrinus may well have been their choice.

These men, if one takes a larger view, were as qualified as either Trajan or Hadrian to be emperor. For one of the results of the coups of 96 and 97 was that the qualifications looked for in a new emperor had become extremely vague. Neither Trajan nor Hadrian had been active senators; both had been too busy as military commanders and provincial governors, so it now seemed that it was an ability to administer a province and to command an army which were the imperial requisites, neither of which abilities had been required of any emperor since Tiberius. Vespasian and Titus had good military reputations but, like Domitian, their military work as emperors was in high command, not active fighting. The four men involved in Hadrian’s pre-emptive coup were all well-qualified in both these new requirements and indeed, better qualified than Hadrian. This may be the basic cause of his killing them.

A plot by Nigrinus looks rather surprising – if he was the choice of the plotters – but it was quite possible; it rather seems as though the plot had been discovered, and that Hadrian then took the opportunity to eliminate the other three men, who were certainly personal enemies of his.5 Their deaths no doubt had as salutary an effect on the attitude of the Senate as had the news of the numerous calamitous uprisings, and this will have been another of Hadrian’s purposes.

Hadrian’s assumption of power, and above all his disregard of the Senate and of its claimed right of determining the succession, was a direct result of the crisis of 96–97. The Senate itself at that time had deliberately broken with the principles of hereditary succession and selection by the reigning emperor, which had been the main elements in the imperial transfer of power since the time of Augustus. Its acceptance of Nerva as emperor in place of the successors chosen by Domitian was a deliberate violation of the practice of imperial hereditary succession, more than a century old by then. The only break before then had been in 68, when Nero had died without an heir or any close relatives. The hereditary principle, which was deeply engrained in Roman society, had been reinstated by Vespasian and had therefore operated for well over a century when Domitian was murdered, though to describe the succession from Augustus to Nero as hereditary is stretching the meaning of the word. It was only by an intricate set of adoptions that the whole scheme could be described as a dynasty.

In 96, however, Nerva’s assumption of power was swiftly ratified by the Senate, which clearly could have chosen someone else in the circumstances, and many of whose members would seem to have had knowledge of the plot to kill Domitian. It is thus reasonable to regard the change in the system as having been accomplished by the Senate quite deliberately, presumably with the intention of senatorial selection becoming the new process. Yet it turned out badly. Nerva was brushed aside; Trajan was imposed on him and on the Senate by the generals, acting in the name of the army, for the good of the Empire of course.

It was this process that now became the model for the succession of Hadrian. He had not needed the validation of a senatorial appointment. Just as with the imposition of Trajan on Nerva, the seizure of power by Hadrian was a military coup d’état, the army imposing Hadrian on the Senate. It is not surprising that his first year was spent (as was that of Trajan) in enforcing his military authority. Rebels were crushed wherever they appeared. Plots were exposed and punished. It is therefore no surprise that of the four men murdered on Hadrian’s orders (though he denied doing so years later, in his autobiography and on oath), three of them were accomplished generals: Palma, Celsus and Quietus. A military man as a new emperor could not allow more distinguished military men to outshine him, and they were just the sort of men who were capable of heading a coup.

Hadrian therefore owed nothing to the Senate, which meant that he had full control over naming his own successor. This, to be sure, was not a new situation, but he did have an exceptional freedom in the matter, comparable in fact to that exercised by the Senate in 96 if the senators had stopped to think rather than greeting Nerva as one of their own becoming emperor. Further, as with both Nerva and Trajan, he had no children and few close relatives. Indeed, he seems to have cordially disliked or even hated those men who were his relatives. Perhaps because of this he made no attempt to single out any one man until the last two years of his life when he became seriously ill. (He was acting, that is, very like Trajan in this, though in Trajan’s case a clear, likely successor did exist in Hadrian himself.)

Hadrian exhibited strong indications of paranoid suspicion all through his reign, beginning with the killings of the four consulars in his first year. He was thus inherently unwilling to name a successor since this might conjure a threat where there had been none before. This did not prevent many men from coveting the throne, but if one voiced an ambition or showed resentment at one of Hadrian’s choices when he finally made one, punishment would follow. The man who he had installed as governor in Syria in 117 when he made himself emperor, L. Catilius Severus, was later made City Prefect. He had served Hadrian for two decades, then was dismissed for and accused of having imperial ambitions.6 Hadrian thus safeguarded himself by preempting any coups organized in the dying days, but he had also to ensure a smooth succession when he did die. In this he improved on Trajan; perhaps this was more the result of his long terminal illness, whereas Trajan had died in the end quite quickly.

So Trajan’s failure to nominate a successor was an example not worth emulating, but Hadrian made heavy weather of his own process of selection. He began by publicly adopting L. Ceionius Commodus as his son, who thus took the name L. Aelius Caesar, but Commodus was a ludicrous choice: old, in bad health and unlikely to live long enough to succeed; a Nerva-like choice. He was also married to the daughter of Avidius Nigrinus, the supposed plotter of 118; possibly his selection was therefore a gesture of conciliation towards the Senate. It may be that Commodus was chosen to be a stopgap to prevent others being suggested or suggesting themselves, and that Hadrian already wanted Commodus’ future son-in-law, Marcus, to be his real successor. In other words, this might be seen as that old idea: the emperor-regent such as Agrippa or Tiberius. It could be that he was chosen so as to deflect plotters, for two emperors were obviously more difficult to kill than one, and it is doubtful if anyone wanted another Nerva situation. Commodus was invested with part of the imperial powers – the tribunician power and the proconsular power, but over the Pannonian provinces only – and sent to the Danube, where there was some trouble. He was also designated as consul for the coming year, 139.7

Two men in particular objected to this procedure and Commodus’ selection: L. Iulius Servianus, Hadrian’s brother-in-law; and Servianus’ grandson, Cn. Pedanius Fuscus Salinator. These two were actually Hadrian’s nearest male relatives and the latter in particular seems to have assumed that he would have been his successor, though there is no evidence that he did any work to earn it or that Hadrian had ever given any indication that way. In reaction to the choice of Commodus he formed a plot, was denounced and executed. His old grandfather was later forced to commit suicide, protesting his innocence and cursing Hadrian as he died. Despite his age of 90, Servianus was clearly seen as dangerous to the emperor’s scheme, and may well have been capable of organizing a coup when the emperor died. Servianus was a highly-distinguished man, having been consul no less than three times, and he had connections throughout the power set in Rome. The deaths of these two men show Hadrian at his most ruthless. He began his reign with consular executions, and he was ending it in the same way.8

The deaths of these two men meant that the path of Commodus to the throne was now unimpeded. He was already invested with much of the authority he would need, and now also had some experience with the army and in governing a province. However, he died, suddenly but hardly unexpectedly, on his return to Rome, on 1 January 138, as he was about to become consul.9

Hadrian thought about the problem for three weeks. He was now very ill himself. This time he organized the nomination differently, summoning a group of senior senators to his sickbed and naming one of them, T. Aurelius Fulvius Boionius Antoninus, as his choice. It is not clear if Antoninus knew of this in advance, but it is certain that he took his own time over accepting. The nomination meeting took place on 24 January (Hadrian’s 62nd birthday), but it was not until a month later, on 25 February, that Antoninus was formally adopted as Hadrian’s son, a procedure that by now had become the essential preliminary step to the succession. He was awarded more of the imperial powers than Commodus ever had: tribunician power, the title of imperator and full proconsular authority, apparently without the provincial limitation that had been imposed on Commodus. This was no doubt one of the reactions by Hadrian to his own illness.

We do not know what occurred in between the two meetings between Hadrian and Antoninus, but the results have all the hallmarks of an agreement reached between them privately. Antoninus was in effect made joint emperor, on the pattern of Nerva/Trajan, Augustus/Tiberius or Vespasian/Titus. Yet there was also another element. It is recognized that Hadrian actually favoured the succession of Marcus Aurelius, his distant cousin, but the boy was still only 16, too young to rule. So Antoninus was also being installed as emperor-regent for Marcus with the duty of ensuring Marcus’ quality upbringing, continued life and political training, and Antoninus’ age rather implied that his stewardship would not last very long.10

The new heir was 51 years old, only eleven years younger than Hadrian himself. He had been consul as far back as 120, and had a daughter, though two sons and another daughter had fairly recently died. He was the son of a consul and grandson of a double consul, a pedigree that should please the Senate, from whose ranks he had indeed been selected. He had never commanded an army, but had certainly had some administrative experience, having administered part of Italy for a time and been proconsul of Asia for a year. Nevertheless, there was a distinct whiff of the Nerva situation about him. His ancestry was from Narbonensian Gaul, though his family had been domiciled and politically active in Rome for at least three generations; he was as Roman as anyone else. His age was perhaps one of the elements in all this that attracted Hadrian since it was unlikely he would rule for very long. Both Trajan and Hadrian died in their early 60s; Antoninus could expect a reign of perhaps ten years or so. This opened the way for the next generation but one to succeed.

It seems clear that the man Hadrian really wanted to succeed him was Marcus Aurelius, who was the son of Annius Verus and the grandson of M. Annius Verus, three times consul, and the colleague of Antoninus’ father in the consulship of 97. This man was also married to a grand-niece of Trajan, so the inheritance was, in this sense, being kept within the family (see Genealogical Table VIII). There was also the young son of Hadrian’s former heir, L. Ceionius Commodus, now called Aelius and in future to be known as Lucius Verus. Both these boys were now brought formally into the line of succession by a series of adoptions. (See Genealogical Table IX.)

As part of the adoption process Antoninus, already adopted as Hadrian’s son, now adopted both Marcus and Lucius as his sons. His own sons were dead, so he was not excluding them. His daughter was to be betrothed to Lucius, though she was a number of years older than him. Hadrian was, in other words, emulating Augustus and perhaps Vespasian, who were the only previous emperors who had gone about the organization of the succession in such a detailed and farsighted way. Augustus had organized the adoption by Tiberius of Germanicus, while Tiberius himself was Augustus’ adopted son, thus determining the succession for the next two generations; and Germanicus himself had sons by that time, one of whom, Gaius, Tiberius had ensured would succeed him. Vespasian had left two adult sons when he died, and did not need to organize the succession quite so obviously. However, Augustus’ scheme failed when Germanicus died only five years after Augustus himself; Germanicus’ son did eventually succeed, of course, as the Emperor Gaius, but this was hardly a happy precedent. Also Vespasian’s succession scheme lasted only a quarter of a century, ending with Domitian, another unpopular if capable ruler. Hadrian might propose a scheme, therefore, but the odds were clearly against it working for more than a couple of decades, or a single generation. Trying to determine the succession in this way meant excluding others who might have legitimate hopes. It might, that is, provoke plots, as it did with both Gaius and Domitian.11


This foreclosing of future options was not necessarily a popular idea, therefore. It was his reaction to all this that brought down L. Catilius Severus, the City Prefect, and at the same time the long-standing Prefect of the Guard L. Marcius Turbo, another old Hadrianic loyalist, and Ummidius Quadratus, a son-in-law of Marcus’ grandfather. None of these men was put to death but merely proscribed or ostracized, so it does not seem that their threat of further action was very serious; perhaps they merely complained.

The surprising thing is not that Hadrian should produce this scheme, but that it more or less worked, surely against the odds. Antoninus succeeded to sole power in July 138, and at once made it clear that his own chosen successor was Marcus. The boy – he was only 16 when Antoninus succeeded – was quaestor the following year, at about the normal age or perhaps a little younger. He was now designated consul for 140 when he was 18 (fourteen years ahead), and five years later he held a second consulship, in which year he married Antoninus’ daughter Faustina (who was transferred to him from Lucius).

Marcus’ marriage was a fertile union, producing children who outlived their father, which made a change. Marcus himself was made the titular joint emperor in 147, being awarded the tribunician and proconsular powers at that time, though his education and training continued for some time yet. This was the timetable that Hadrian (and perhaps Antoninus) had surely envisaged when he arranged the succession and the adoptions. Had Antoninus died at the same age as Trajan and Hadrian, Marcus would have become sole emperor about the time he was granted these imperial powers. His age was then 25, the same age as Gaius when he succeeded Tiberius (and about the age of Domitian when he succeeded), but his education had been much more rigorous, even practical. Above all, he was much more clearly singled out as the future emperor than Gaius had been. Marcus was, in fact, the first man to go through a successful training for the imperial office. No one else, before or after, ever did.

As Antoninus was dying in 161 (having reigned for twenty-three years and reached the age of 74, somewhat surprisingly) he clearly nominated Marcus as his successor (the process done by Trajan and Hadrian), and Marcus next day attended the Senate. He put on a show of reluctance to take up the sole power, thereby giving the Senate – which had no choice – the opportunity of insisting.12 So Marcus collected the final powers, including the office of pontifex maximus, but he also insisted that Lucius Verus, his adoptive brother, be made joint emperor with him. The Senate did as he wished; again, it really had no choice. There were thus two emperors, Marcus being marginally the senior, reminiscent of the joint Augustus/Agrippa, Augustus/Tiberius and Vespasian/Titus combinations, though the most obvious precedent was Nerva/Trajan, for Cassius Dio claims that Lucius Verus was the military half and Marcus the non-military half of the partnership.13

Lucius Verus died in the winter of early 169, leaving no surviving children, and Marcus therefore continued as the sole emperor for several years. When he himself died several of his daughters were still alive, but only one son, six other sons having died before him. For the first time in a century an emperor was succeeded by a son of his own body. The boy, Commodus, was only 18, but he had been granted the imperial powers several years before: first the proconsular imperium, so that he might join his father in a joint triumph, then consul at the age of 15, and then the tribunician power. This was the same set of powers his father had held, but all about ten years earlier.14

Marcus was rather more respectful of the Senate than Trajan and Hadrian had been, following in this the attitude of Antoninus, whose whole adult life had been spent as a senator. He had scrupulously involved the Senate in the progress of his son to the position of joint ruler, but it was very clear that he was doing so for dynastic reasons and the Senate in fact, as usual, had no real choice in the matter, though to be fair there is no sign that there was any dissent over Commodus’ promotion.

Marcus’ reign is notable for an attempt to supplant the ruling emperor by an armed rebellion, the first since Domitian’s reign. Since it failed it is generally reckoned to be a usurpation, but investigation rather suggests that the story is not an attempt like that of the successful Galba or the unsuccessful Scribonianus, though it had elements of both of these. This is the case of Avidius Cassius, the first of a series of superficially similar actions that took place over the next two centuries and more, and as such it deserves a fairly detailed treatment. It is, however, also a rather unusual example, and by no means easy to relate to other cases.

Usurpation in fact is a modern value judgement that should not be made, for it implies that the usurper is in the wrong, or rather that those ‘usurpations’ that succeeded, and so the ‘usurpers’ becoming regarded as legitimate emperors, were therefore mounting righteous rebellions. So Galba, condemned as a public enemy by the Senate and so as a heinous rebel, was then welcomed by that very same Senate, when Nero died, as the saviour of the state. Vitellius and Vespasian, who were both counted as legitimate emperors, began in the same way. Classifying unsuccessful rebels as usurpers is therefore pointless: ‘unsuccessful emperors’ will be the formation used here, or even simply emperor. These men proclaimed themselves as alternatives to the ruling emperors, sought support, minted their own coins and exerted their imperial authority in the territories where they were recognized. They might be proclaimed emperors, at times against their will, by others. In the third century these men can be counted in dozens, and their purposes and types will be considered later (see Chapters 8 and 9). They tended to ignore Rome and to fasten their hopes on part of the army stationed in the provinces; Galba is thus the archetype, also Vitellius and Septimius Severus, but Trajan was as potent an example. This is yet another legacy of the events of 96–98.

M. Avidius Cassius was a successful governor and army commander, in office as governor of Syria from 169, following the conclusion of the war with Parthia that had occupied much of the previous decade. He had also been given a general supervisory role over the ‘orient’, an area that seems to have included Egypt and parts of Anatolia as well as Syria, Palestine and Arabia. This was a position recalling that of Domitius Corbulo under Nero, and of Agrippa under Augustus. He was also the direct successor in the East of the Emperor Lucius Verus, a factor of unknown potency.

Cassius was therefore the most powerful man in the Empire after the emperor, Marcus Aurelius. He was a comparatively young man, born in Alexandria about 130, the son of a high official of Hadrian’s called Heliodorus, whose wife claimed to be descended from the Hellenistic Seleukid dynasty by way of the kings of Kommagene. He was therefore in many ways a local boy in the East, with connections throughout the area for which he was responsible. He had also been brought up in close association with the court of Hadrian and Antoninus Pius, and he was much the same age as Lucius Verus, his predecessor, and of Marcus’ wife Faustina.

He had exercised power in the East for a decade, first as the commander of one of the columns that invaded Mesopotamia in 165, then as governor of Syria from 169. It is clear that he had the trust of Marcus Aurelius, who was very busy over much of that time fighting on the Danube frontier. His brief would be to maintain the peace with Parthia, since the Empire could not afford to fight two major enemies at the same time. He had at one point to put down a minor rebellion in Egypt, but otherwise he was a successful governor. We have no details, but the fact that he held the position until 175 is clear evidence of his success and of the emperor’s favour.

In 175 he had himself proclaimed as emperor. The trigger is said to have been a report of the death of Marcus, who was known to have been ill, but this is not a sufficient explanation by itself for Cassius’ action. The further detail that makes it convincing is that he was asked by Faustina to take up the imperial office in the guise of emperor-regent for her surviving son Commodus, who was only 13 in 175.

This makes some sense of a curious episode. Cassius was well-known to Faustina and the court. He was experienced and capable, as his record showed, and presumably he was therefore trusted. Marcus, in the aftermath, is said to have regretted that; since Cassius had been killed, he had lost the opportunity to exercise clemency. When the news arrived in Syria that Marcus was still alive and well, Cassius was killed by his soldiers and his son Maecianus by other soldiers. His daughter Alexandria was spared.

This scenario is not unfamiliar from the previous two imperial centuries; the model was clearly Plotina and Hadrian. Cassius was solicited to proclaim himself emperor by Faustina, who believed Marcus to be dying, and she clearly envisaged him acting as protector of Commodus. This was a position that Augustus had envisaged for Agrippa, then for Tiberius, and Tiberius for Sejanus; it was the position into which Hadrian had put Antoninus, emperor-guardian for Marcus. (Faustina’s anticipation of Marcus’ death is reminiscent also of Domitian’s action as Titus lay dying.)

Faustina and Cassius were thus working within a recognized process and system. That it became regarded as a rebellion was due to the emperor’s unexpected recovery from his illness. Cassius was clearly too quick to respond to the news, though he was accepted as emperor throughout the Eastern provinces; not surprisingly since he had governed them since 169.15 This is in fact exactly what happened with Hadrian; the only thing missing was senatorial recognition. It was not the Senate that stopped him, but the news reaching the soldiers that Marcus still lived; the soldiers therefore killed Cassius in part to cancel out their earlier acceptance of him as emperor.

The main result of Cassius’ action was to accelerate Commodus’ progress towards power. He was put through the ceremony of adulthood before Marcus marched off to the East and was simultaneously made princeps iuventutis, marking him as heir to Marcus. On Marcus’ return Commodus was awarded the several imperial powers, putting him in the position of joint emperor. So when Marcus died in 180, only four years later, Commodus, like his father, only required such offices as pontifex maximus to be given him to acquire the full official powers as emperor. The exact process is not noted in any source. Commodus was on the northern frontier for some months after Marcus died; presumably the Senate dutifully voted him the details in his absence. The precedent would be Trajan and Hadrian.

Commodus’ youth when he became sole ruler surely raised doubts in some senatorial minds about an emperor, the sole ruler of the whole Roman Empire, taking office at such an age. The precedents – Nero and Gaius – were hardly encouraging. Marcus had been singled out as the heir by that age, but his education and training went on for another ten years or so after that. It seems unlikely that Commodus would submit to a teacher now that he was sole emperor. It also seems that Marcus himself had doubts, for he left in place a ring of administrators chosen by himself for their integrity and ability, who were to operate the administration for the new emperor. However, with Marcus dead Commodus had the powers of appointment and dismissal, and having others to do the hard work was hardly good training. He was, despite his position as joint emperor over the previous half decade, essentially untrained for the post, perhaps deliberately so, for Marcus’ long training had maybe been tiresome and stultifying, and he may not have wanted his only surviving son to go through such an experience, and there was nothing either the Senate or Marcus could do about it. Marcus was trapped in the requirements of heredity and with only one surviving son, he had no real choice. This was the real legacy of the coup d’état of 97; the Senate had lost all control over the succession and could not interfere in the emperor’s wishes. Everyone was stuck with Commodus.

The Emperors of the Crisis of 193


Commodus (180–192).


Pertinax (January–March 193).


Didius Julianus (March–June 193).

The Contenders of 193 and After


Septimius Severus (193–211). (Adobe Stock)


Pescennius Niger (193–194).


Clodius Albinus (193–197). (Sailko via Wikimedia Commons)

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