Pax Romana

by Adrian Goldsworthy

  It is clear that units regularly sent detailed strength returns to the provincial legate, while the culture of inspection meant that legions and auxiliaries alike did their best to prepare in advance. An early-second-century-AD writing tablet found at Carlisle in Britain gives a glimpse of a routine internal check:

  Docilis to Augurinus his prefect greetings. As you ordered, we have attached below all the names of lancers who are missing lances, either who did not have fighting lances, or who (did not have) the smaller subarmales [probably a type of jerkin worn with a cuirass] or who (did not have) regulation swords.

  No reason is supplied for the missing items, so we cannot know whether they were lost on active service, through natural wear and tear, neglect or theft.18

  The strength and condition of army units, their mounts and other equipment were matters of concern for any emperor. Military victories won by his legates were attributed to the princeps, even if he was far away when the action was fought, but conversely he would also be held responsible for any defeat. The governors of military provinces were expected to preserve the loyalty, readiness and efficiency of the army under their command. To aid them in this task, the army’s bureaucracy kept them in regular contact with individual units and commanders. The records generated in these exchanges were clearly held in central archives – some surviving documents show signs of being kept up-to-date and many refer to copies. In the early years most legates appear to have based their headquarters and these archives in a legionary base, but as time passed dedicated facilities were constructed for them. In the late first century AD, a palace and fort with barracks were built at Londinium for the legate of Britain. Although the legate spent much of his time on the road to hold assizes or perform his military role, these centres became a form of provincial capitals and acted as administrative centres for an army stationed there.19

  It is harder to know how much information routinely passed from the provincial headquarters to Rome. Legates reported to the emperor on many issues, and no doubt the state of the provincial army featured in this, but it is less clear how much detail was included unless specific requests for information were made. Some things were centrally recorded at Rome. From Claudius onwards, all auxiliaries gained citizenship when honourably discharged. These additions to the census of Roman citizens were documented at Rome – the soldier being given a bronze copy of the text confirming the grant. In AD 6 Augustus established the aerarium militare or Military Treasury to deal with army pay and the bounty or land given to demobilised legionaries. At the very least this meant some collation of soldiers’ entitlements, even if much of the administration of salaries was carried out by the unit itself.

  There was certainly central control of officers’ commissions, including the posts given to senators as senior tribunes, legionary legates and provincial legates, and the more than 500 equestrian military commands. There were some 1,800 legionary centurions at any one time, a mixture of men commissioned after service in the lower ranks and those directly appointed. The majority spent the bulk of their military career as centurions, for this was a grade of officer rather than a specific rank, and centurions varied considerably in responsibility and prestige, as well as pay and bonuses on a scale some five to ten times greater than those of the rank and file. A significant proportion of centurions served in more than one legion, whether to get a better posting or to gain steps in rank. For instance Caius Octavius Honoratus was an equestrian directly commissioned into Legio II Augusta in Britain. He then transferred in succession to Legio VII Claudia pia fidelis in Upper Moesia on the Danube, to XVI Flavia firma in Syria, and finally to X Gemina in Upper Pannonia, once again on the Danube, finishing as princeps posterior of its fifth cohort. This was the fourth senior grade of centurion in an ordinary cohort, and it may be that he rose a step each time he transferred to a new legion. Even more wide-ranging was Petronius Fortunatus, who was centurion for no less than forty-six years, serving in a dozen different legions, stationed in Syria, Lower Germany, Upper Pannonia, Britain, Numidia, Syria again, Lower Germany again, Britain again, Arabia, Cappadocia, Italy and finally either Upper or Lower Pannonia. His son was also a centurion, but died only six years after he was commissioned having served in two legions.20

  Centurions were often stationed away from their legion, like the man Pliny mentioned who was sent to Byzantium to regulate traffic. Therefore it is possible that some of these transfers were nominal, and that the officer did not actually travel to join each unit, but remained where he was and simply gained a step in promotion. Both men’s careers are recorded on their tombstones and do not explain how the system worked. There were six centurions in cohorts two to ten and five in the first cohort of a legion, perhaps with another in charge of the legionary cavalry, giving a total of fifty-nine or sixty per legion. Our evidence does not suggest that this total was ever exceeded, or that there were serving centurions unattached to a legion. In some cases men transferred between legions stationed in the same province, but others, like Honoratus and Fortunatus, were posted from one end of the empire to the other. Unit records report the addition of officers appointed from outside, noting that it was by order of the provincial governor. Yet it is hard to believe that governors of different provinces arranged transfers on their own authority, and such careers strongly suggest a central administration to keep track of vacancies and appointments.21

  We do not know how this worked, and it is unlikely that an emperor hand-picked every centurion or equestrian officer in the army and kept a close eye on their careers. Appointments at all levels were determined as much or more by patronage than the talent of the individual involved. Pliny once wrote to the legate of a military province asking on behalf of an equestrian friend for a commission, probably as junior tribune in a legion. ‘Your command of a large army gives you a plentiful source of benefits to confer and secondly, your tenure has been long enough for you to have provided for your own friends. Turn to mine – they are not many.’ The recommendation of a governor to commission or promote someone, whether on the basis of his own observations or the urging of a friend, stood a good chance of being confirmed by the princeps, as long as the governor was in favour and had not made too many requests. Such matters were dealt with by those responsible for imperial correspondence, the ab epistulis. An extension of an aristocrat’s household and secretariat, for much of the first century AD this office was supervised by an imperial freedman. Afterwards the post was given to an equestrian procurator.22

  The loyalty of the army was the ultimate guarantor of an emperor’s power. A sign of rebellion was to tear down the imagines, the images of the princeps and his family kept with the standards (which had caused such uproar when Pilate had them brought into Jerusalem). No emperor would let a provincial governor make himself too popular with the army in his province, and especially its officers. This was one of the main charges against Calpurnius Piso, the legate of Syria dismissed by Germanicus in AD 19. According to Tacitus, Piso’s tenure as governor saw a concerted effort to win over his soldiers, with his wife helping by attending troop reviews and exercises:

  . . . by bounties and bribery, by attentions to the humblest private, by dismissals of the veteran centurions and the stricter tribunes, whom he replaced by dependants of his own or by men of the worst character, by permitting indolence in the camp, licence in the towns, and in the country a vagrant and riotous soldiery, he carried corruption to such a pitch that in the language of the rabble he was known as the Father of the Legions (parens legionum).23

  The Senate’s decree condemning Piso talked of his illegal attempt to resume command of Syria, leading to a brief civil war. Soldiers who opposed him were executed,

  . . . many without hearing their cases, without consulting his staff, and by crucifying not only foreigners but also a centurion, a Roman citizen; he had destroyed the military discipline established by the divine Augustus and maintained by Tiberius Caesar Augustus, not only by allowing soldiers not to obey in the traditional
manner those in command of them, but also by giving donatives in his own name from the fiscus [treasury] of our Princeps, a deed which, he was pleased to see, led to some soldiers being called ‘Pisonians’, others ‘Caesarians’, and by going on to confer distinctions on those who, after usurping such a name, had shown him obedience . . .24

  In AD 14 mutinous legionaries of the Rhine army wanted to proclaim Germanicus emperor in place of Tiberius, an offer he refused. There were abortive risings by provincial legates against Claudius and Domitian. The legate of Britain executed by the latter for permitting a new design of lance to be named after him was seen as trying to ingratiate himself with the troops. Officers, and especially centurions, were the key to controlling the legions. The emperor was the ultimate source of patronage and the arbiter of careers, and he could not afford to let anyone else gain too much influence over these. Senators needed to be permitted a share of favours to pass on to their clients, but no one senator – still less a family or other closely linked group – could be permitted to decide on too high a proportion of promotions and appointments, especially for the garrison of a particular province.25

  The office of the ab epistulis issued commissions and kept records tracking appointments in their archives. This meant that those working in this office, and especially the man in charge, were able to influence decisions and could be lobbied to grant favours. The poet Statius describes a freedman serving in this role under Domitian as recommending men for commissions as centurion or equestrian tribune. In addition to this office and its archives, there were the frumentarii or ‘grain men’, originally formed to supervise the supply of food to the army. Legionaries seconded from their units to the legate’s staff, these men became couriers travelling back and forth to Rome, carrying despatches, but also able to report on events and conditions in each province. At any one time as many as half of them would be stationed at Rome waiting to be sent out, and over time their role grew. In later years, especially by the third century AD, they gained a grim reputation as imperial spies, concerned with any hint of disloyalty on the part of governors or other officers, but from the start they offered another source of information to the emperor and his advisors.26

  THE OTHER SIDE OF THE HILL

  Emperors relied on maintaining a monopoly of military power. Senatorial legates were necessary to lead the armies and govern provinces, but each of these men could become a rival if backed by the legions placed under his command. Thus the army posed a potential threat as well as being the basis of their rule – a situation the Emperor Tiberius described as ‘holding the wolf by the ears’. Augustus established the army at a size convenient for his needs both to secure his dominance and to win him military glory from expansion. Maintaining the army was expensive, the burden growing as it increased in size in the years to come. More legions were unnecessary to secure the emperor’s position against internal rivals, and indeed presented greater opportunity for over-ambitious provincial governors to challenge him. A partial exception to this was the enlargement of the praetorians and other units stationed in or near Rome, although it was not until the reign of Septimius Severus that these became equivalent in numbers to a provincial army.27

  Over time, more legions and auxiliary troops were raised in spite of the cost. Military pay changed less. Domitian increased the annual salary of a legionary from the 225 denarii introduced by Julius Caesar to 300. This was far from lavish, but was supplemented by periodic bonuses or donatives, issued to mark special occasions such as the accession of an emperor. Septimius Severus, victor in a civil war and nervous of losing his troops’ support, increased both salary and bonuses. Allegedly his death-bed advice to his sons and successors was to ‘indulge the soldiers and despise everyone else’.28

  As we have seen, by far the greatest part of this highly expensive army was stationed on or near the frontiers of the empire, and it is clearly important to understand why this was done. In recent decades an intense scholarly debate has raged over the role of the army and the nature of Rome’s frontiers. Although fruitful in many ways, all too often it has polarised and oversimplified the issue, so that the army’s role is depicted as either offensive or defensive rather than varying over time and sometimes combining aspects of both. Much like the discussion of Roman imperialism, there has been a regrettable tendency to focus exclusively on Roman aims, ideology, methods and resources and to ignore those of their neighbours. It is well worth considering the wider world before we look at the function of the Roman army.29

  Rome faced no foreign power capable of matching her strength. By far the largest and most sophisticated neighbour was Parthia, ruled by the Arsacid dynasty of once nomadic aristocrats who had seized much of the old Seleucid Empire. Early contact with Rome in the first century BC was diplomatic, and marked by the Romans’ usual bullish disdain for foreigners. Then came Crassus’ unprovoked attack, his subsequent defeat at Carrhae and the looming threat of Parthian invasion of the Roman east that preoccupied Cicero and later became a reality in 41–40 BC. Syria was overrun and Parthian allies invaded Asia and were installed in power in Judaea. Although they were ejected from all these areas a few years later, Mark Antony’s counter-attack through Armenia ended in disaster.30

  Civil wars distracted both sides during this period, and throughout its existence the Parthian monarchy was rocked by bloody power struggles between members of the royal house. Their empire was divided into lesser kingdoms and satrapies, each of these local rulers a powerful figure and potential backer of rivals. The Surenas – probably a title rather than a name – defeated Crassus, only to be executed a few months later by a king who did not wish a subordinate to win too much glory. Parthian armies consisted of a core of royal troops, but relied heavily on contingents provided by the lesser kings and rulers. Some of these troops were more or less full-time soldiers, and many more were called upon to serve in times of war out of obligation to the nobility. The Surenas is said to have taken 10,000 horsemen with him when he went on campaign or travelled on official business.31

  We hear little of Parthian foot soldiers in our sources, even though it is likely that there were significant numbers of these. Some were archers or other skirmishers. There is no impression of significant numbers of close-order infantry able to match legionaries or auxiliaries in close combat. The main strength of every Parthian army was its cavalry. A minority – perhaps around 10 per cent – were cataphracts, with horse and rider both heavily armoured. These carried bows, but their principal tactic was a charge – delivered at a trot, given this weight of armour – using a long, two-handed lance called a contus. Horse archers were in contrast highly mobile, wore little or no protective armour and instead relied on speed to avoid enemy missiles. Carrying a powerful recurved composite bow – so called because when unstrung the bow bends back in the opposite direction – they concentrated less on accuracy than on deluging the enemy with clouds of arrows. Only when their opponents were weakened by casualties and demoralised would horse archers try to charge home and ride them down. The heavy and light cavalry worked best when closely co-ordinated, the cataphracts waiting for the right moment before launching their attack. All the while Parthian drummers pounded kettledrums to intimidate the enemy.

  Well led and in open country, a Parthian army was highly formidable, as Carrhae had shown. Crassus and Mark Antony both discovered that it was very difficult to retreat from this mobile enemy, the latter only escaping with heavy casualties. When Antony did win a victory he failed to inflict decisive losses on the Parthians because their cavalry scattered and fled at speed. Yet clear victories were possible. His legate Ventidius twice beat the Parthians by luring the cataphracts into rash attacks against strong hilltop positions before his legionaries had been sufficiently worn down by archery. Many encounters between Roman and Parthian armies ended as standoffs, each side waiting for the other to make a mistake. Although difficult to defeat, the Parthians often struggled to win. With their soldiers mainly non-professionals, there was a limit
to how long a Parthian army could remain in the field before contingents dispersed to their homes. Supply was another problem, made worse by the need to feed and care for so many horses. Rudimentary knowledge of siegecraft and the difficulty of keeping an army in one place for any length of time meant that it was difficult for them to capture or starve into submission fortified towns or cities.32

  Under Augustus the Euphrates was confirmed as the effective boundary between the Roman and Parthian empires. It did not represent a natural cultural or ethnic boundary. Many people spoke Aramaic on both sides of the border, and there were substantial Greek communities living under Parthian rule – after Antioch and Alexandria, Seleucia was probably the largest Greek city in the world. There were also large numbers of Jews in Babylonia, who maintained links with the wider Jewish community and, until its destruction, travelled to worship at the Temple in Jerusalem. Trade between Rome and Parthia was always common, the border never closed, even if people passing across it were usually aware of when they had crossed it. Kingdoms such as Commagene, Osrhoene and Armenia lay between the two empires and had long-standing connections to communities in both. Although the Seleucids and before them the Persians had at times controlled territory as far as the Mediterranean coast, this wider region was no more a natural unit than the realm of the Parthian king or the eastern provinces of Rome. Occasionally Roman sources represent the Parthians as laying claim to the lands of these old empires, but there is little sign of deep ambition to seize them.33