The Praetorian Guard had played an enormously important part in the imperial politics of the first century AD. This also coincided with our richest body of written evidence for the Roman Empire. The second century is entirely different. A succession of strong and competent emperors contributed to a period of unprecedented stability for the Roman world. In this context, the praetorians had no opportunity or, it seems, wish to play any part in toppling or appointing emperors. The written canon of evidence also dramatically declines in quantity and quality, leaving us principally with only a series of much later biographies of the emperors, and the epitome of Cassius Dio. The picture that emerges is of a Praetorian Guard that took part in imperial campaigns, such as Trajan’s Dacian wars, and also continued to operate as a police force in Italy.
Domitian’s unpopularity amongst the wider public meant that his assassination caused little or no disquiet. Only the army seems to have been bothered. His use of praetorians to help fight the Dacian war meant that their first response to news of his death was to demand his deification. The only factor that prevented an immediate military uprising in Rome was the lack of any obvious leader. In the event, that position was filled by the prefect Casperius Aelianus in a brief return to the days when the praetorians shaped the course of Roman history, but he took his time before acting.
Marcus Cocceius Nerva’s accession as emperor was clearly a stopgap. In the summer of 96 Nerva was approaching his sixty-fifth birthday and he had no children. There was therefore no question of a new dynasty, though he did have relatives. The ageing new emperor reappointed Casperius Aelianus to the praetorian prefecture, probably to calm down the Guard and the rest of the army. It seems to have worked to begin with. Nerva issued coins in gold, silver and brass, showing two clasped hands grasping a legionary standard with the legend CONCORDIA EXERCITVVM, ‘Harmony of the Armies’.
Nerva emptied the prisons of those accused of treason, condemned informers, returned property that had been appropriated by Domitian, and sought out sound advisers. Despite this, he was still the victim of plots, his age at accession being the main reason for unrest. The first was led by a senator called Calpurnius Crassus. An informer told Nerva what was happening, so Nerva outfaced the plotters by providing them with a chance to kill him, even handing them weapons. This was followed by another, led by Casperius Aelianus, who had whipped up the praetorians to demand the execution of his immediate predecessor, Titus Petronius Secundus, and Domitian’s freedman Parthenius. He next encouraged the praetorians to mutiny. Nerva’s considerable personal courage won out again, this time when he bared his neck and invited them to slit it. He survived, but at the expense of Petronius and Parthenius. Nerva knew he was vulnerable and came up with a solution. He selected a promising soldier, a Spaniard called Marcus Ulpius Traianus (known to us as Trajan), and adopted him as his heir. Trajan had a family connection through being the son of Marcia, sister-in-law of Titus.
The behaviour of the praetorians during this time was strangely muted, despite Aelianus’ efforts. They never successfully avenged Domitian, for all their demands that he be deified. Given the time and effort Domitian had expended on massaging the sensibilities of the army, and the role the praetorians had played in acclaiming him in 81, their relative inertia is a little surprising. On the other hand, the crucial factor was perhaps the one Suetonius had observed: there was no obvious champion they could plant on the throne, like Claudius in 41. Moreover, the actions of Aelianus had made him a marked man along with the praetorian mutineers. Pliny the Younger, writing in his Panegyric of Trajan, referred to the mutiny with unequivocal horror: Nerva’s authority had been ‘snatched’, thanks to the breakdown of military discipline. Nevertheless, this does not explain why Aelianus remained in post. Nerva probably feared risking a further confrontation with the Guard by disposing of him, unless Aelianus was involved in the arrangements to appoint Trajan as Nerva’s heir. Indeed, the appointment of Trajan may have formed part of Aelianus’ demands.
Nerva died on 25 January 98 after a reign of a few days over sixteen months. Trajan, who was still with the frontier armies in Germany, did not actually reach Rome until late 99, apparently preferring to consolidate his hold on the vital Rhine and Danube garrisons. Aelianus and the mutineers were summoned, on the pretext that Trajan had a job for them. This ruse not only removed them from Rome, but was also a trick. Aelianus’ only hope would have been to topple Nerva and replace him with his own choice of emperor. Since that had not happened, Trajan was confronted with a praetorian prefect of suspect loyalty, or at any rate someone associated with an emperor (Domitian) who was now being popularly demonized as part of the establishment of the new regime. Aelianus and the mutineers were ‘put out of the way’, an ambiguous term that might mean they were executed or simply cashiered and dispersed, regardless of whether or not Aelianus had helped facilitate Trajan’s adoption. Trajan replaced Aelianus with Sextus Attius Suburanus Aemilianus. He handed Suburanus his sword of office and told the new prefect to use it on his behalf if he ruled well, and use it to kill him if he ruled badly. Suburanus held the post until c. 101, when he was replaced with Tiberius Claudius Livianus who was sole prefect until possibly as late as c. 112.
Trajan’s first public appearance in Rome in 99 was attended by an enormous crowd. According to Pliny, ‘the soldiers present’, who must have been praetorians given that this was in Rome, were dressed as civilians and consequently indistinguishable from everyone else. This may of course have been relatively normal for praetorians but the point being made by Pliny is surely that the praetorians represented no military threat or presence because there was no need to under an emperor who was completely in control. This of course reflects Pliny’s obsequious relationship with an emperor and benefactor he revered, but there was probably some truth in it. Interestingly, Trajan decided to pay only half the accession donative to the soldiers, whereas the amount promised to civilians was paid in full. The reason appears to have been to make a public gesture that Trajan was not seeking to bribe the soldiers into supporting him, whereas the civilians ‘who could more easily have been refused’ were therefore the more deserving.
The question arises here of whether the equites singulares Augusti, the ‘imperial mounted bodyguard’, belong to this date and even whether Trajan brought them with him to Rome from the frontier. They served with the Praetorian Guard in the same way as mounted auxiliary units did with the legions, forming an elite mounted praetorian wing, and had a base on the Caelian Hill. This does not mean they necessarily got on with the ordinary praetorians. They certainly existed by 118 because an unprovenanced and fragmentary diploma refers to the unit with a consular date for this year, though no veteran soldiers’ names are preserved. It is possible that the unit existed even earlier, on the evidence that some attested soldiers’ names include Flavius, which would suggest a foundation under Domitian. What is not clear is whether the equites pushed the praetorians into a subordinate role or operated in a collaborative function, providing a fast mobile bodyguard for an emperor in the field and freeing up praetorians for fighting. The career of Ulpius Titus, although he lived in the late second or early third century, is of interest here. He was selected for the equites singulares Augusti after having served as a cavalryman in a Thracian auxiliary cavalry wing. Thracian cavalry had served in the Roman army’s auxiliary forces for centuries and provided some of the most experienced and important mounted troops in the whole Roman army.
The praetorians themselves seem also to have increased in number by this time, if not already under Domitian or even as early as Vespasian. A diploma from Vindonissa (Windisch) in Germania Superior dated to the year 100 under Trajan clearly refers to the existence of the X praetorian cohort, which presumably had been added at some point between 76 and 100, most likely by Domitian. This makes it possible there were now ten praetorian cohorts from this date. However, a tenth cohort does not help us by confirming the total number of praetorians, or the size of individual cohorts, now or at any other time. Nevertheless, some authorities have assumed that it does, for example arguing that the Guard was made up of ten milliary cohorts thereafter.
Indeed, the praetorians seem to have enjoyed Trajan’s favour. A fragmentary relief from Puteoli, stylistically attributable to the early second century and probably from an arch of Trajan, depicts two praetorians with shields embellished with scorpions associated with praetorians. This is a stylized representation of the Guard in a symbolic setting, and quite unlike the way praetorians are featured at war on several panels on Trajan’s Column in Rome. The reliefs represent the start of a period when artistic representations of praetorians become more frequent and an impression can be gained of how they might have appeared. Of course, the sculptures also tend to depict the praetorians on campaign. There must have been several reasons for this. Such images flattered the praetorians’ vanity, showing them as the emperor’s right-hand men in action. They also showed the praetorians as a military force, and in this capacity were a useful reminder that the emperor ruled with powerful military backing.
The Trajan’s Column reliefs depict his Dacian wars against Decebalus and show the praetorians taking an active part in the campaigns. This was a trend that continued and become the norm during the second century. In the ‘first battle’, praetorians, identifiable from their wreathed standards, stand in the background behind legionaries. Later, a squad of praetorians accompanies Trajan as he is about to embark on a galley; they are his only accompanying troops. Subsequently he reaches a military base with his praetorians in tow, where they are met by legionaries and auxiliaries. Although it is impossible to tell how many praetorians were involved (our principal source, Dio, provides only a brief account of Trajan’s campaigns), there are some attested examples of individuals. Lucius Aemilius Paternus had a distinguished career as a centurion, serving at one point in the IIII praetorian cohort when he was decorated for his service in Dacia. He went on to fight in Parthia for Trajan too. Gaius Arrius Clemens served as both an infantry and mounted praetorian in the VIIII cohort in the Dacian war. He was also decorated, receiving ‘necklaces, armbands and ornaments’. Clemens was later to rise to be an aide to the praetorian prefects, and subsequently a centurion in the VII cohort under Hadrian, when he was decorated again.
During Trajan’s reign these men served under the prefect Tiberius Claudius Livianus who is attested in Dacia being sent by Trajan to negotiate with Decebalus. These men’s careers, and the depictions on Trajan’s Column, show that the Guard was functioning now really as part of the general Roman army rather than as a distinct and privileged separate unit based in Rome. By the late first century and thereafter, the Praetorian Guard was the only Rome-based military unit to participate alongside conventional troops in the field; the urban cohorts and the vigiles routinely stayed in Rome where of course their services were essential for public order and safety.
Since the purpose of the Guard was to protect the emperor’s person, it was only logical that they would participate in wars in which he was personally involved, but the way they were used does illustrate how the Guard was evolving into a part of the regular army. Lucius Laelius Fuscus expired at the age of sixty-five after forty-two years’ military service. From being an eques in the Praetorian Guard he had progressed through various positions to serve as centurion of the I cohort of the vigiles, centurion of the military police (statores), centurion of the XIIII urban cohort, centurion of the X praetorian cohort and, finally, holding the prestigious position of centurion trecenarius of the VII legion Claudia. The style of the inscription on his marble urn is late first or early second century as far as the reign of Hadrian. The VII legion Claudia participated in Trajan’s Dacian and Parthian wars, raising the possibility that Fuscus had been transferred from the Guard during one of those occasions, though there is nothing to substantiate this.
From hereon there is little mention of the Guard in any other capacity until the reign of Commodus, under whom they seem to have degenerated into institutionalized indolence until they were cashiered by Septimius Severus in June 193. However, evidence from Marcus Aurelius’ reign half a century after Trajan shows the praetorian prefects operating as police in Italy, and it is quite possible that this role was already by then well established as the much earlier evidence from Pompeii before 79 suggests. The single most conspicuous problem with the Praetorian Guard after the reign of Trajan until the reign of Commodus is that it is rarely referred to in the extant sources. For this period we are mainly reliant on what remains of Cassius Dio, which for this era only exists in the form of a later epitome, and the biographies of the emperors known as the Scriptores Historiae Augustae, which were not composed until the fourth century. For the long period of the reigns of Hadrian (117–38) and Antoninus Pius (138–61), the Guard as an organization is virtually ignored. More is known about praetorian prefects, but otherwise the story can only be pieced together from fragments.
Trajan died in Cilicia in 117, suffering from a sickness that was followed by a stroke that left him partly paralysed. His successor Hadrian was the grandson of Trajan’s aunt, Ulpia. Although his side of the family was originally Italian, they had settled in Italica in Spain, where Trajan was from. After his father died when he was ten, Hadrian was placed under the guardianship of Trajan. Hadrian pursued a successful senatorial military and administrative career and early in Trajan’s reign married the emperor’s great-niece, Sabina, becoming a particular favourite of Trajan’s wife Plotina. Hadrian went on to fight in Trajan’s Dacian campaign and proceeded through a number of other posts, including the tribunician power in 105 and then governor of Syria, the post he held when Trajan died. It was an extremely unusual situation. Although Hadrian’s position as heir looks obvious, at the time it was anything but. Other candidates were believed to be favoured by Trajan, such as the famous lawyer Lucius Neratius Priscus. In the end a rumour circulated that Plotina fabricated the claim that Hadrian had been adopted by Trajan on his deathbed. The letter that confirmed this was sent to Hadrian, arriving on 9 August 117, and he was promptly acclaimed emperor by the army in the province, just as Vespasian had been in 69. This equivocal situation made it all the more necessary that Hadrian assert his position extremely quickly. He requested from the senate the deification of Trajan and tactfully apologized on behalf of the troops for acting presumptuously in acclaiming him as emperor.
Publius Acilius Attianus had been praetorian prefect for about five years by 117 and was with Trajan when he died. As far back as 86 Attianus had been the guardian of the ten-year-old Publius Aelius Hadrianus (Hadrian), along with Hadrian’s cousin, Trajan. He seems to have shared the prefecture since around 112 with Servius Sulpicius Similis, a modest man who had taken the post reluctantly after he had been prefect of Egypt; earlier in his career he had risen to the heights of primus pilus. When he was still only a centurion Similis was once summoned by Trajan ahead of the prefects. The deferential Similis said ‘it was a shame’ for him to be called in while prefects waited outside. Sent ahead by Hadrian, Attianus returned to Rome with Trajan’s ashes, which were to be placed at the base of his column in the forum, accompanied by Plotina and her niece Matidia (the mother of Hadrian’s wife, Sabina). Attianus seems to have written to Hadrian with the advice that he should order the execution of Baebius Macer, prefect of Rome, on the grounds that there was reason to believe he might object to Hadrian being emperor. Perhaps Macer was known to prefer Neratius Maximus. Other potential objectors were cited by Attianus. Whatever the truth, the outcome is unknown, though Macer was probably at least removed from post.
A senatorial plot to murder Hadrian soon after his accession was thwarted, but it resulted in the senate ordering the execution of four senators. Hadrian denied that he had wanted this, but it marred the beginning of his principate and had implications for the praetorian prefecture. Hadrian hurried to Rome, arriving there on 9 July 118, and offered a large handout to the people in order to offset the unpopularity the executions had caused, and made a number of other conciliatory gestures such as remitting private debt owed to the state. Attianus was awarded the honorific promotion to senatorial status of consular rank in 119. Hadrian appears to have had an ulterior motive. He allegedly believed that Attianus had been behind the execution of the four senators, and resented his power, which of course included the potential power of the praetorians themselves. Supposedly reluctant to be associated with any more executions and also wishing to transfer all the blame for the senatorial executions, Hadrian coerced Attianus into resigning. It is equally possible that Attianus was a loyalist who had carried out Hadrian’s secret wishes and been prepared to take the blame on the emperor’s behalf. If so, it would have made him a good example of how useful the position of praetorian prefect could be to an emperor in a way that had nothing to do with commanding the Guard. The position with Similis is harder to understand. Hadrian’s biographer implies that Similis was another victim of what is described as Hadrian’s plan to remove the men who had smoothed his path to power. Dio, however, suggests that this unassuming man had some trouble in persuading Hadrian to release him. Similis went on to enjoy seven years of retirement, regarding these as the only years he had enjoyed life; all the years of his career he dismissed as being no more than merely existing. This was recorded on his tombstone.
Attianus and Similis were replaced as prefects in or around 119 by Gaius Septicius Clarus and Quintus Marcius Turbo. Turbo, who had a very significant military reputation, seems to have had a longer personal association with Hadrian. As a young man Hadrian served as tribune of the II legion Adiutrix while it was stationed in the province of Pannonia Inferior. Turbo, at some point in his career, was a centurion with II Adiutrix since the tombstone found at Aquincum (within Budapest) of a soldier called Gaius Castricius Victor states that he was in Turbo’s century. There is no certainty that Turbo’s time in II Adiutrix coincided with Hadrian’s, or even that this is the same man. But they might have served with the legion simultaneously, and if so then they might have come into contact and the future emperor been impressed by Turbo, though a personal connection may have played a more important part in Hadrian’s decision.
Turbo was to have a remarkable military career both before and after his appointment as praetorian prefect. He made some of the previous incumbents seem like dilettantes. By 114 Turbo was commanding the imperial fleet at Misenum. Next under Trajan he seems to have been sent to lead an assault on Jewish rebels in Egypt and Cyrene, leading a naval force and one of combined infantry and cavalry. The action was successful and involved the death of a large number of rebels. Soon after Trajan’s death, Hadrian sent Turbo to crush a rebellion in Mauretania. This was evidently also so successful that Hadrian, exceptionally, appointed Turbo temporarily to be an equestrian prefect governor of the important frontier garrison provinces of Pannonia and Dacia. This was so unusual that it must reflect Turbo’s remarkable skills. The only major governorship normally allocated to an equestrian prefect was Egypt, reflecting that province’s nature as the personal property of the emperor; indeed, as governor of Dacia Turbo was considered to hold a rank equivalent in prestige to being prefect of Egypt. The appointment came rapidly after the execution of the four senators and will have involved Hadrian dismissing the consular governor, Lucius Minucius Natalis. The practical effect was to place his own man in charge of an important component of the army. Perhaps Hadrian had in mind Maecenas’ advice to Augustus around 150 years previously on the advantages of distributing patronage amongst the equestrians. Turbo rearranged Dacia into two provinces. Dacia Superior was demoted to the status of requiring only a governor of praetorian, not consular, rank, and Dacia Inferior was to be governed by an equestrian procurator.
Turbo took his new post of praetorian prefect extremely seriously. He lived like an ordinary citizen and passed the day in the vicinity of the palace, even punctiliously checking up on everything late at night. He transferred his morning salutation (salutatio) to the late evening, greeting his friends and clients then, rather than during the day when he was far busier doing his job. Accordingly, the lawyer Cornelius Fronto dropped in to pay his respects after a dinner party, paradoxically greeting Turbo with the evening departure vale (‘farewell’), rather than the morning salve (‘good health’). Turbo was said to have operated on the principle that as prefect he ‘should die on his feet’.
The prefect Gaius Septicius Clarus had been a friend and correspondent of Pliny the Younger. He also had a senator for a nephew. Clarus had urged Pliny to publish his letters and was rewarded by having the collection dedicated to him. Suetonius also dedicated part of his Lives of the Caesars to him. Although Clarus’ earlier career is completely unknown to us, he had probably served in some capacity as an equestrian commanding officer, perhaps commanding an auxiliary infantry unit. His personal tastes and interests were more literary. This probably formed the basis of Hadrian’s decision to appoint him to serve as a convivial and interesting companion rather than as a military official. Hadrian set out for the northern frontier in 121, accompanied by Clarus, presumably with part of the Guard too, as well as Suetonius, his imperial secretary.
Hadrian was away until 125. During this time he paid particular attention to military discipline. While we have no specific information that this was applied to the Guard it must have done, especially with Turbo in charge of those left in Rome. The choice of Septicius Clarus and Suetonius as travelling companions seems to have backfired. Around 122 Hadrian visited Britain where he initiated construction of the wall that bears his name ‘to separate the barbarians from the Romans’. At this point in his biography we are told he dismissed both Septicius Clarus and Suetonius, along with several other unnamed people, for being too familiar with Sabina. He was even tempted to divorce Sabina but stopped himself on the basis of the dignity of his office. It is clear from the structure of the biography that this event is placed during Hadrian’s stay in Britain, but since the biographies of this period are notoriously confused in detail in some places, the actual sequence of events may have been different. Quite what had happened is unclear, but there was a suggestion of sexual impropriety, even if it amounted to no more than indiscreet flirting. Aurelius Victor includes a reference to Sabina’s claim that she had deliberately avoided becoming pregnant by Hadrian because she considered him so ‘inhuman’ that she wished to save the human race from any of his offspring. Hadrian had clearly found out about the carryings-on from his spies, the frumentarii, whom he used for all sorts of private investigations in his household and circle of friends. Septicius Clarus had been added to Attianus and others whom Hadrian had once trusted and now regarded as enemies.
An occasional instance of a military career that included a spell in the Guard is available at around this time. Titus Pontius Sabinus was a career legionary who, as primus pilus of the III legion Augusta, was placed in charge of detachments of the VII Gemina, VIII Augusta and XXII Primigenia sent on ‘the British expedition’ around this time, perhaps accompanying Hadrian. The province had been in considerable difficulties since around the end of Trajan’s reign. After this foray into the wilds of Britain, Sabinus was promoted to be tribune of the III cohort of the vigiles, tribune of the XIIII urban cohort, and then tribune of the II praetorian cohort, before becoming primus pilus once again and finishing up as procurator of the province of Gallia Narbonensis. This shows how much experience was considered necessary for a man to hold the tribunate in the Praetorian Guard. His time as tribune of the II praetorian cohort probably occurred under the latter part of the reign of Hadrian. A praetorian denied the chance to accumulate any experience at all was Lucius Marius Vitalis. He joined the Guard when he was around sixteen or seventeen years old during the reign of Hadrian. He left Rome with the Guard, headed for some unknown destination, perhaps with Hadrian, but died aged seventeen years and fifty-five days. Marius Vitalis illustrates how the original Republican tradition of hiring praetorians from experienced soldiers had been at least partly replaced by recruiting very young men. Men of Pontius Sabinus’ calibre therefore found themselves knocking into shape youths with little or no experience at all of soldiering, and who would have taken some time to turn into praetorians with the right skills to serve the emperor either in Rome or in the field. This goes some way to explaining the rationale behind the decision over half a century later in 193 to cashier the Guard and replace it entirely with legionaries who had considerably more to offer in the way of experience.
Meanwhile, the man who replaced Septicius Clarus and continued to command any members of the Guard in Hadrian’s retinue is unknown. That Turbo had remained in Rome is only likely, and not an attested fact. The most obvious choice to replace Clarus would have been the former prefect of Egypt (117–19), Quintus Rammius Martialis; however, not only is there no information to that effect, but unless he was with Hadrian already there would have been something of a delay before he could either fill the post or join him. Hadrian was to remain abroad until 125, finishing up in Sicily by way of Greece before returning to Rome.
For all his skills and experience, Turbo also fell foul of Hadrian’s capricious inclination to turn against those he had trusted, even though Turbo, like Similis, had been honoured with a statue. He was said, along with others, to have been ‘persecuted’, though what that means, or its consequences, is unknown to us. This may not have occurred until Hadrian returned to Rome in 134. The same applies to the Praetorian Guard at this time. We seem to know a remarkable amount about Turbo’s career before he became praetorian prefect and the manner in which he conducted himself in the post, but little or nothing about the praetorians themselves or how he led them. We can only assume that praetorians accompanied Hadrian on his journey between 121 and 125 because Clarus went with him. In 128 Hadrian visited North Africa, returned to Rome and then headed off to the eastern provinces, including Greece, Syria, Arabia and Egypt. We can do no more than speculate on how the praetorians regarded being removed from the privileged comforts of the Castra Praetoria in Rome. If Septicius Clarus had not been replaced, which is quite possible, then Turbo may have been out of Rome with Hadrian on some of his later travels serving as sole prefect; equally, he may have remained in the city with the prefect of Rome, Annius Verus, with a tribune instead commanding a detachment of the Guard accompanying the emperor.