15
THE STRUCTURE OF EMPIRE BEFORE AND AFTER CONSTANTINE
Constantine’s victory over Licinius left him in possession of the part of the empire in which his formative years had been spent, but where he had not set foot since 305. He now determined to make it his home and mark that fact with a new foundation, a city in his name and in his own image – Constantinople. Built on the site of ancient Byzantium, at the crossroads of Europe and Asia, the ceremonial foundation and ground-breaking for the new city took place on 8 November 324: as so often, the emperor wasted no time once he knew what he wanted to do. He claimed to have had a vision directing him where to build the city and a divinity also helped him lay out its boundaries. It would be six years before the city was habitable (the dedication was on 11 May 330), and its status as a second Rome was not cemented for many decades thereafter. But by the end of the fourth century, Constantinople was indisputably the capital of the eastern empire.
At the same time as he dedicated his new city, Constantine proclaimed as caesar his second son by Fausta, named Constantius after his paternal grandfather, adding him to the caesars Crispus and Constantinus in the imperial college. Constantius would prove the longest-lived of all Constantine’s sons, and the one who most clearly cemented his father’s legacy as the founder of a very different Roman empire than the one Augustus or Trajan or Severus had ruled. Before returning to the narrative of Constantine’s sole reign, it is worth understanding the structures of the empire he created, for they are the foundations for understanding the political narrative of the remaining chapters and also this volume’s sequel.
That Constantine created a new Roman empire has never been in doubt. A hundred years ago, before the concept of late antiquity as a period with a historical dynamic all its own had really taken root, it was commonplace to mark the divide between the ancient and medieval worlds as the year 312. Nowadays, we mark that divide less sharply, and place it much later, but that question of periodisation has not diminished our assessment of Constantine’s role in transforming how the empire was governed. He built directly upon foundations laid by the tetrarchs, and it is not always easy for us to distinguish Constantinian initiatives from those of Diocletian, Galerius and Licinius, or from those of his son Constantius II, who systematised and standardised many of his father’s more ad hoc measures. This chapter will sketch the chief differences in the administration of the empire from the Antonine world in which our story began to the emergent late imperial state of the Constantinian empire.
In many ways, the late empire can be understood as the natural outcome of the long process of equestrianisation that we have encountered so many times in the course of our narrative; the ways in which practice and ideologies of government were transformed by bureaucrats and bureaucratic methods. These meant that governmental uniformity could be envisaged as a real possibility in a way that it could not in the second century or before. And then the juridical Romanisation of the empire that followed Caracalla’s universal citizenship grant of 212 made uniformity seem that much more desirable. The degree to which the late empire’s ideological outlook depends upon the high imperial ordo equester follows from the second-century change in the balance between senators and equestrians.
Under the republic, there had been a very fl uid boundary between those men who possessed the equestrian census of 400,000 sestertii but chose not to pursue public office and those who did so. Augustus created the legal basis for distinguishing the ordines, first by raising the minimum senatorial fortune from the ancient equestrian census of 400,000 sestertii to the more substantial million sestertii (not in itself a huge fortune when a moderately rich man might have an annual income larger than that), but also by making senatorial status heritable within a family down to the third generation. Along with the new property requirements, Augustus stabilised the number of senators at around 600 men, revised the leges annales (the age at which the different magistracies could be held), and formalised the rules according to which the senate met. With those measures, it became possible not only to maintain the basic cursus honorum of the old republican magistracies, but to build on them and accommodate them to a new world in which power flowed from a single man, and where senators could not leave Italy without imperial permission.
The Augustan reform established the basic size and shape of the senatorial order that it would more or less preserve until the merging of the two ordines in the fourth century. Throughout the early imperial period, and certainly under Hadrian where our story began, the number of available senators was only ever minimally sufficient to fulfil the many tasks that were expected of them. Even with the annual influx of the sons and grandsons of senators from the twenty minor magistracies (the vigintivirate) and into the quaestorship, the natural tendency of senatorial families to die out had to be countered, either by the imperial adlection of experienced men directly into the higher ranks of the ordo, or by the adlection of the sons of successful equestrian officials in amplissimum ordinem, which allowed them to seek office as if they had been born into the ordo senatorius. The pressure on senatorial numbers was the result of both the individual roles senators had to play and the number of functions the body had to serve as a collective institution. For centuries after the inception of imperial rule, the senate continued to serve as the primary legislative and juridical body of the empire, which meant that a substantial quorum of senators had to be permanently in place in Rome. At the same time, the expanding empire needed senators – former praetors and consuls – to run it. The reason that additional ‘suffect’ consuls were appointed at intervals during the course of the year, after the ‘ordinary’ consuls had taken office on 1 January, was to provide sufficient ex-consuls to staff offices of consular rank in the imperial administration.
In the ten ‘public’ provinces, proconsuls continued to be chosen by lot and to serve for a single year, in a formalised version of the old republican promagistracy, with responsibility for jurisdiction, administration and peacekeeping with whatever auxiliary troops were stationed in the province (legions were not stationed in public provinces). Yet almost every imperial province needed a senatorial governor as well, serving as legatus Augusti pro praetore for a period of time limited only by the imperial pleasure. Additional legionary legates were needed in provinces with more than one legion, because a single governor would have a dangerous level of power if he were allowed complete control of several armies. Each of these posts required men of at least praetorian, and more usually consular, rank; in the largest consular commands – Tarraconensis, Cappadocia – an additional praetorian iuridicus, or legal officer, was needed to supplement the consular legate’s limited time for dispensing justice to Roman citizens in the province. Augustus and Tiberius had also created a whole series of new senatorial posts for Rome and Italy, including the urban prefecture – always the preserve of a distinguished and particularly honoured consular – and a variety of other praefecti and curatores for financial and judicial positions. Below the praetorian and consular ranks, junior senators were needed as adiutores, ‘assistants’, to more senior magistrates throughout the empire, both in public and imperial provinces.
From the end of the first century, the pressure of business in the Greek provinces, many of which consisted of numerous independent and semi-autonomous communities, required the frequent appointment of special officials known as correctores to oversee a city or region’s local affairs. Already at the end of the Julio-Claudian period, at least 145 senatorial officials were needed annually, a number that had risen to more than 160 by the accession of Marcus Aurelius in the year 161. Moreover, the tendency of eastern senators to have purely eastern careers affected available manpower right through the third century. There was, in other words, a constant tension between a need to maintain the dignity of the senate by keeping its membership fairly restricted and the need to administer the empire effectively.
That was a need that never slackened, since by the second century the empire covered roughly 2 million square miles and there was sometimes just one senatorial (or senior equestrian) official per 350,000–400,000 inhabitants. As a result, the first emperors leant heavily both on the familia Caesaris, particularly their own most trusted freedmen, and on the ordo equester. As the imperial system expanded, so too did the number of positions needed to manage it. These could not easily be filled by senators, even had enough of them been available: the new offices lacked sufficient prestige, because they were personally dependent on the emperor in a way that was less obviously true of the old republican magistracies, and they therefore offended against the polite fiction that the empire was not actually an autocracy. Initially, moreover, some of the tasks entrusted to equestrians (the praefectura annonae, for instance) required long tenures of office which would have interfered with a senator’s progress through the traditional cursus, something that men of high status could not be asked to tolerate. The careful balancing act of the early empire, in which monarchy was disguised behind the facade of republican institutions, was therefore made easier by using equestrians to staff new posts as they were created. Normal Roman conservatism ensured that posts that had been filled by men of a particular rank for any length of time would usually continue to be so. So while nearly all the most prestigious offices in imperial government remained in the hands of senators for centuries, much of the actual machinery of government fell to the ordo equester.
Under the republic, young aspirants to the senate, who necessarily possessed the equestrian census, began their careers as junior officers in a legion, generally as military tribunes. However, after the creation of the new ordo senatorius under Augustus and Tiberius, the vast majority of the military tribunates and all the prefectures of auxiliary units were reserved to equestrians; under Claudius, the so-called tres militiae of an early equestrian career (praefectus cohortis, praefectus alae, tribunus militum) were formally codified. Such posts served as training grounds for men who would go on to staff an ever-expanding imperial hierarchy, and by the middle of the second century there were as many as 550 junior commands available to equites in the army. The two praetorian prefects had been equestrians since the office was created, and that prefecture remained, with the prefecture of Egypt, the most senior equestrian post until the ordo itself disappeared.
We have encountered many of the other, more junior, equestrian offices in the course of our narrative. In the immediate orbit of the emperor, there were officials responsible for imperial correspondence (the ab epistulis), dealing with the embassies of Greek cities (ad legationes et responsa Graeca), replying to petitions (a libellis), investigating legal cases in which an imperial interest was required (a cognitionibus), the administration of imperial finances (a rationibus), these including private estates (patrimonium) and mints (moneta), the inheritances due to the emperor (procurator hereditatium) and the various indirect customs tolls known collectively as portoria. In the second century, a new entry-level post of advocatus fisci allowed equestrians to enter the financial bureaus without having held a junior military command first, and also allowed the rhetors and other members of the eastern educated classes to share in the honours of Roman government, even if it was the sole office they ever held. Some of the tasks previously undertaken by a single official were split at this time as well – for instance, that of ab epistulis, which was split into Latin and Greek divisions, thereby giving the educated classes of the main Greek cities a direct route into imperial government. Under Hadrian or Pius, the whole new bureau of the res privata was created to distinguish the personal property of the imperial family from the patrimonium that had, since the end of the Julio-Claudian dynasty, come to be associated with the imperial purple rather than the man who wore it. This new patrimonium privatum or res privata was thenceforth staffed by its own hierarchy of equestrian officials in Italy and the provinces, and exploded in size after the confiscations that followed on the defeats of Pescennius Niger and Clodius Albinus during the civil wars of 193–7.
The city of Rome also fed the growth of the ordo equester. Leaving aside the praetorian prefects, the most important equestrian officials were the praefectus annonae, in charge of the food supply, and the praefectus vigilum, used for firefighting and occasional policing when the praetorians proved recalcitrant or insufficient. Equestrians were also employed as administrators of the imperial gladiatorial schools (procuratores ludi), head librarians of the imperial library (a bibliothecis), transport chiefs (praefectus vehiculorum) and as procurators responsible for collecting the taxes on inheritance and on the emancipation of slaves (procuratores vicesimae hereditatium and vicesimae libertatis) and collating the data from provincial censuses that were vital to the collection of those taxes (a censibus).
The senatorial curatores for temples and for the aqueducts (curatores aedium sacrarum and aquarum) had equestrian chiefs of staff by the second century. In the provinces, the prefect of Egypt had been an equestrian since the reign of Augustus, holding an imperium equal to that of a proconsul and taking over wholesale the administrative structure put in place by the Ptolemies, which was likewise now staffed mainly by equestrians. Many small provinces had equestrian procurators playing the role that a senatorial praeses would fill elsewhere, although whenever such provinces developed real military importance, they were transferred to the command of senatorial legates, as happened at various times to Judaea, Cappadocia, Thracia, Noricum and Raetia. The prefects of the Tyrrhenian and Adriatic fleets, stationed at Misenum (now Bacoli on the bay of Naples) and Ravenna respectively, were equestrians, as were at least seven attested provincial fleet commanders serving under the provincial governors. More pervasively, a dozen financial procurators in the imperial provinces and another ten or more financial procurators administered the imperial patrimony in the public provinces. As mining became an important source of imperial revenue in the second century, so it became necessary to appoint procurators to supervise the imperial revenues from it in Dalmatia, Pannonia and eventually in Dacia as well, though in other provinces imperial freedmen might still undertake the task.
Then, as the second century progressed and Roman citizenship became ever more widespread, a number of tasks that had previously been unnecessary, or so rarely necessary that they could be handled by a governor’s staff, now required the extension into the provinces of equestrian bureaus previously active only in Italy; this was most visibly the case with the procuratorial staffs responsible for the taxes on inheritance and emancipation that only citizens paid. Equally, as is the natural tendency of bureaucracies, many of these hierarchies developed increasing complexity and required multiplications of effort, so we find growing numbers of subpraefecti and subprocuratores from the early second century onwards. The procuratorial service alone doubled in size between the Trajanic and Severan eras. Moreover, imperial procurators increasingly took on the financial roles in public provinces that had formerly been the work of senatorial quaestors, and sometimes intervened in affairs that had nothing to do with the administration of either the imperial patrimony or the taxation of the province.
Unsurprisingly, as such equestrian posts multiplied, they began to form a cursus honorum comparable to the senatorial cursus. Though much more flexible, because not dependent on the old hierarchy of the republican magistracies for its structure, the equestrian cursus had certainly hardened into a recognisable hierarchy by the time of Commodus, when equestrian offices were organised according to their pay grades as sexagenarii, centenarii, ducenarii and trecenarii, which is to say, offices to which were attached salaries of 60,000 and 100,000, 200,000 or 300,000 sestertii per annum. Again, just as a senator was a vir clarissimus, so was an equestrian a vir egregius (ho krátistos in Greek), or, from the time of Marcus, a still more prominent vir perfectissimus (ho diasemótatos).
The growth of equestrian offices, though clearly taking place on a very large scale throughout the first and second centuries, is difficult to trace in detail because our literary evidence is heavily biased towards the activities of senate and emperor, and because epigraphic and papyrological evidence is not enough to fill the gaps. Thus the first attestation of an equestrian post may come decades after it was actually created, which distorts our understanding of chronological details without altering the overall picture of ever-expanding equestrian responsibilities. This expansion had an impact on the horizons and the outlook of elite society across the empire. The ordo senatorius was in the first instance a hereditary caste, even when it became more common to adlect men, especially those who were already an emperor’s trusted allies, directly into its ranks. Senate membership implied a personal relationship to the emperor right through the Antonine period, whether a senator was the scion of an old family whose offspring had to be taken into account or a man who had come to the emperor’s attention and been adlected into the ordo: once adlected, the legal requirement that senators transfer a large proportion of their wealth to Italy and take up residence there kept these new families locked in the imperial orbit. Indeed, throughout the principate, and even after Marcus loosened the strictness with which Italian residency was enforced, a senatorial posting came in a codicil signed by the emperor himself and perhaps even written out in his own hand.
The ordo equester, by contrast, always remained an economic class, distinguished by its gold rings as clearly as were senators by the latus clavus on their togas. Entry to an equestrian career in imperial service could come at a much greater physical and social distance from the person of the emperor than could a senatorial career – as is illustrated by the fact that appointment to lower equestrian posts came via epistulae from the bureau ab epistulis, rather than via an imperial codicil. At the lower end of the equestrian order were men who had risen from the ranks of the common soldiery, ex-centurions who had held the senior non-commissioned post in their unit (the primipilarii) and for whom an equestrian office was the culmination of a long career. At the uppermost end, the wealthiest and best-connected members of the ordo could expect, or aspire to, adlection to the senate, or at least permission to pursue a senatorial career late in life after admission to the vigintivirate.
The vast majority of equestrians fell somewhere in between, as the census requirement which remained the only qualification for equestrian rank was never ruinously high. Partly for that reason, many equites never left the municipal world of their origo or entered imperial service; even so, if they came to the notice of the right person, their sons might be granted the latus clavus and with it the right to start on the senatorial cursus. But in the simplest, most practical way, the need for personal contact with the emperor shaped and circumscribed the senatorial order, which was much less diverse geographically as a result. High imperial senators tended to cluster in distinct regions within distinct provinces – southern Hispania and Narbonensis from the time of Nero; Asia, Achaea and Bithynia et Pontus after Vespasian; proconsular Africa and far eastern provinces like Cappadocia from the time of Marcus Aurelius. The equestrian ordo was spread more thickly on the ground throughout the ‘civilised’ provinces of the empire and even beyond them, numbering perhaps in the tens of thousands. In part because of this geographical diversity and physical distance from the imperial court, members of the ordo equester were more dependent on vertical relations of patronage, often at several removes from the emperor, for advancement and preferment. While the Roman upper-class ideology of the ordo senatorius, dating back to republican precedents, downplayed the necessity of experience or special skills as prerequisite for office, the ordo equester became relatively more professionalised thanks to its numbers and geographical diversity, with promotion at least plausibly on the basis of merit rather than simply on birth.
Birth did remain the primary factor in access to power for a long time: the ordo senatorius retained its lock on the most senior and the most prestigious of imperial posts through to the very end of the second century. The most powerful equites might be honoured with consular symbols – consularibus ornamentis ornati, as it was put – but they did not themselves hold even the suffect consulship. Only in the reign of Severus do we begin to see changes that laid the groundwork for the later empire. One of the main things that separates the Severan empire from the Antonine is the unembarrassed acknowledgement of an equestrian elite as the chief ministers of state. That was perhaps a natural result of brutal civil wars that had divided and depleted the senate, and of the purges that accompanied the Severan victory. Yet it is also clear that Severus never really trusted his fellow senators; the Severan empire witnesses a real sea change in the balance of senators and equestrians at the highest levels of government. Severus massively expanded the old res privata in order to handle mass confiscations from former followers of Niger and Albinus and, before long, this res privata subsumed the old patrimonium and became the most important financial bureau in the third-century state, its staff entirely equestrian. In the public provinces, where the census had formerly been the prerogative of the local communities, the use of equestrian procuratores ad census accipiendos was extended from the imperial provinces. More and more often, as inscriptions in particular make clear, it was minor imperial officials – or soldiers seconded from their units, acting for and reporting back to the financial bureaus – who collected taxes in cash and in kind, replacing both tax farmers and local councils.
If this expansion of the financial administration reached deepest into provincial life, changes to military commands were equally dramatic. The first legions to have permanent equestrian praefecti rather than senatorial legati from the time of their formation were the I, II and III Parthica, which had been raised to prosecute Severus’s wars. His new province of Mesopotamia was organised on the Egyptian model, with an equestrian praeses and equestrian prefects for its legions. As we have seen, minor provinces had always been governed by procurators of equestrian rank, but Severus began to extend the practice to major military provinces as well, doing so with the polite fiction that such directly appointed equestrians were merely ‘acting’ (vice agens) for an absent legate. Caracalla was blunter, promoting large numbers of equites to the senatorial order and thus qualifying them for senatorial offices, even when they lacked any experience of, or feel for, the senatorial cursus. Before long, even official sources started to use the title praeses indiscriminately for the governors of both imperial and public provinces.
As these early Severan precedents took hold and were imitated by the precarious successors to his dynasty, the number of senatorial families with very recent equestrian roots continued to rise, while the Augustan and Flavian aristocracies all but disappeared from the consular fasti. Within the single generation that separated Macrinus’s failed reign from the death of Gordian III, an eques like Philip could look like a plausibly imperial figure. In the course of the same generation, the administrative fiction of governors ‘vice agens’ was discarded and the status of provinces could change as equestrian praesides replaced senatorial legati. By the second half of the third century, Arabia, Baetica, Dalmatia, Numidia, Pontus-Bithynia and Germania Superior had all been transferred to equestrian control, while only one of the provinces created in the third century – Phrygia-Caria in 249/50 – was entrusted to a senatorial legatus and only a few of the large old provinces like Hispania Tarraconensis continued to be governed by legati.
After the otherwise unremarkable Vitulasius Laetinianus and C. Iulius Sallustius Saturninus Fortunatianus, who served in the reign of Gallienus, we can identify no legatus legionis of senatorial background. The new mobile cavalry units that became central to the military system under Gallienus were all commanded by equestrian praepositi. Likewise, by the time of Gallienus, holders of the highest equestrian offices, which brought with them the rank of eminentissimus, might frequently reach the consulship, thereby changing their rank to that of the senatorial clarissimus without their having held any post in the senatorial cursus. Such men almost never went on to further office after attaining the clarissimate, but it was nevertheless impossible for such changes not to cause some confusion of the senatorial and equestrian cursus, and eventually of the senatorial and equestrian ordines.
As the senatorial and equestrian cursus became blurred, civilian and military careers overlapped less and less, in a way that foreshadowed the explicit Constantinian division of civilian from military cursus. Right into the reign of Severus Alexander, men who had reached the pinnacle of a career in the ranks were then drafted into the equestrian civil service, but as the third century progressed that became rarer and rarer: soldiers who rose to be primipilarii ceased to become civilian procurators, the last one known to have done so being Aurelius Sabinianus, who served during the reign of Valerian and Gallienus. Gallienus, more even than his early third-century predecessors, had a habit of placing junior equestrian officers straight into legionary commands that would once have been held by legati legionis, with the title of prefect and the rank of viri egregii, and of naming similar men duces – a new generic title for a field commander holding great discretionary powers.
The officer corps that was created in this half-accidental manner finally brought Gallienus down, for all the senior officers who plotted his overthrow – Aureolus, Heraclianus, Marcianus, Claudius, Aurelian – derived from precisely this background, as later did Diocletian’s senior caesar, Constantius I. It is quite clear that the military crises on several fronts that so affected the middle years of the century required experiment and expedient measures, and it may also be true that Gallienus – remembered as the scourge of the senate in the fourth century – could make so pragmatic a use of equestrians in senatorial positions precisely because his own senatorial background was beyond reproach. Of the other third-century emperors, however, only Trajan Decius had followed a senatorial cursus, while the rest, where we can ascertain anything of their early careers, had risen through the army to an equestrian command before acceding to – or seizing – the purple.
The multiplication of equestrian experts in government brought with it a new sense that it was possible to manage things in fundamentally reproducible and impersonal ways across provinces, and without the ad-hoc-ery that had characterised republican and early imperial governance of the provinces. By the reign of Severus Alexander, reproducible, universal practices were beginning to homogenise the vagaries of provincial governance, in part because the enfranchisement of the whole population by Caracalla meant that Roman law had to be extended to regions where it was previously barely known. At the end of the third century, Diocletian and his co-emperors saw the systematic value of bringing practical, managerial aspirations of governance together with an ideological uniformity. By the end of the tetrarchy, the last remnants of an early imperial system that distinguished between the emperor as privatus, the emperor as princeps and the Roman state he led had disappeared. With them went most of the vestigial trappings of the republic that Augustus had deliberately enshrined. The minor senatorial offices had already started to disappear earlier in the third century: the vigintivirate, the tribunate of the plebs and the plebeian aedileship are all unattested after the time of Gallienus, after which a token quaestorship marked the beginnings of a senatorial cursus. Under the tetrarchy, the quaestorship became little more than a hidden tax allowing the sons of senators to formally enrol in the ordo senatorius, as it remained after Constantine suppressed the equestrian ordo and replaced it with a hierarchy of senatorial ranks.
Another legacy of the third century was the reduction in the number of praetorships, made redundant by mid-century, when all the formerly praetorian governorships had become equestrian. In this period, we likewise cease to hear of the old senatorial correctores and iuridici in Italy, those honourable ad hoc appointments that had, in the first and second centuries, provided senatorial administration throughout the peninsula’s districts. In their stead, a new and permanent breed of corrector is first attested under Probus, implying a provincialisation of Italy that would be formalised by the second tetrarchy of Galerius. Under the tetrarchs, the last consular provinces – Tarraconensis, Phrygia and Syria–Phoenice – became equestrian as well, while the remaining public provinces of Achaea, Crete and Cyprus were transferred to full imperial appointments, following on the transfer of Macedonia and Lycia-Pamphylia under Probus and Carus.
Constantine thus inherited a vastly altered landscape, one that had already made permanent many of the ad hoc experiments of the third century. His own reforms cemented the extensive and coercive state that the tetrarchy had begun to systematise. Whereas the tetrarchic model had dispersed power among first two and then four emperors in order to bring third-century political violence back under control, Constantine ensured that his own hold on power was absolute. He kept in place the tetrarchs’ increasingly intrusive hierarchy of state government, its voice bombastic, its ceremonial simultaneously inclusive and distancing. But he also recognised the value of the older, Antonine model of an emperor who communicated with such subjects as could get near him, responding to their petitions with grace and magnanimity. For that reason, whereas Diocletian’s governing voice had insisted on the centrality of officialdom to the care of the empire, Constantine inaugurated a hectoring style that promised to protect his subjects from the very officials he himself had set to govern them. He inflicted harsh and exemplary punishments on officials who offended against his subjects and preyed upon them, treating such offences as attacks upon his own dignity. He thus sought to appeal directly to his subjects in a way that Diocletian had not, while doing so in the heightened emotional style that Diocletian and his lawyers had pioneered. For Constantine, it was the deliberate gesture of a charismatic ruler, one who used the apparatus bequeathed him by the tetrarchy to govern, but who addressed his subjects directly as their champion and protector. This ostentatious distancing of himself from the very officials who governed the state that he embodied was in part a function of the constant expansion of that state, an expansion that is the single most visible feature of his reign and of those that followed.
At the base of the fourth-century system there was provincial government, the Severan provinces that had been split up and multiplied under Diocletian. The main evidence for these provinces is a bureaucratic document from early in the joint reign of Constantine and Licinius known as the Verona List (Laterculus Veronensis), which lists the more than 100 provinces into which the empire was divided. Provincial governors had different titles – proconsul, consularis, corrector – and they came to signify a hierarchy of rank and prestige among different provincial commands. As heirs of the oldest senatorial provinces of the republic, the proconsuls of Africa Proconsularis, Asia and Achaea were marked out by the special legal privilege of reporting directly to the emperor, rather than to a higher official like the prefect. For the most part, the governors all had similar functions, the whole civilian administration of their province, including both the legal system and the province’s obligation to the various financial bureaus of the state. The outline and number of provinces was relatively fungible, with new ones created over the course of the fourth and fifth centuries and various changes made in their status and provincial boundaries.
The dioceses – those larger units into which provinces were grouped by the tetrarchs – tended to be much more stable. Their primary function seems at first to have been fiscal, placing together regions that were subject to the same hierarchy of tax officials. They were initially governed by subordinates of the praetorian prefects, often acting as vice-prefects or plenipotentiary representatives. By the time of Constantine, however, diocesan governance had become more systematic, under officials called vicarii, who had the authority to judge legal cases vice sacra, that is to say, in the imperial stead. The goal of this was both to provide better justice to a solicitous emperor’s beloved provincials and to ensure that different layers of increasingly complex appellate jurisdiction would overlap one another, and thus provide surveillance of both the officials and provincials. It was probably the same need for greater and more coherent oversight that caused Constantine to split Diocletian’s Moesian diocese into Dacia and Macedonia, and Valens, late in the fourth century, to separate Egypt from Oriens under its own vicar, known as the praefectus Augustalis (the vicar of Oriens was also uniquely styled, as comes rather than vicarius Orientis). Throughout the fourth and well into the fifth century, the dioceses remained the building blocks of empire, the administrative level at which divisions between different emperors’ spheres of influence were marked. Despite that, vicarii never gained inappellate legal powers: just as a provincial governor’s decision might be appealed to a vicarius or a prefect, so too a vicar’s judgement could be appealed before the emperor or the praetorian prefect.
These late imperial prefects were the direct descendants of the early imperial officials we have seen throughout our story. Quite early in the fourth century, they did indeed come to have inappellate judicial powers, their judgements standing as unchallengeable as an emperor’s. Under the tetrarchy, each emperor had had his own praetorian prefect, and that practice continued as Constantine gave his children subordinate courts in different parts of the empire. The prefects had lost their vestigial military powers after Constantine suppressed the praetorian guard in 312, but they remained the most powerful officials in the imperial state, judging in the stead of the emperor, collecting and disbursing the revenues of the dioceses under their authority and hearing appeals against lower ranking regional officials. Their financial responsibilities were enormous, because they were responsible for the annona – all the pay and rations of the imperial civil service and the army. Because the late empire as much as the early empire was essentially a machine that redistributed tax from the provinces back out as pay, in cash or kind, to the emperor’s servants and soldiers, the officials in primary charge of that machine could not help but have a preponderance of power and responsibility. Along with their basic responsibility for the redistribution of wealth, the prefects oversaw the upkeep of the imperial infrastructure, maintained the public postal system and the private shipping networks that were paid to carry the annona and levied taxes in cash, in kind or in conscription of unpaid labour to see that those functions were fulfilled.
By the time of Constantine’s death, the de facto territorialisation of the prefects’ jurisdiction is noticeable in the sources, and quite clearly so in the reign of his son Constantius II. Though the dioceses that pertained to the prefectures might shift at times (and did so frequently in the later fourth and early fifth centuries, thanks to civil wars and invasions), four relatively stable prefectures grew up by around 350: a prefecture of Gallia, generally administered from Trier and taking in Britannia, the two Gallic dioceses and Hispania; a prefecture of Italy and Africa, taking in Italy, Latin-speaking Africa west of Cyrene, the Alpine provinces and sometimes Pannonia; a prefecture of Illyricum that was sometimes administered jointly with Italy and Africa, and taking in Macedonia, Dacia and often Pannonia as well; and a prefecture of the east, taking in Thrace, Asia Minor, the Levant and Mesopotamia and Egypt. The provinces of Achaea, Asia and Africa Proconsularis were not subject to the prefect’s authority, though in practice they needed to work with his administration in financial matters. Nor was Rome (or, after 359, Constantinople), which was governed by the praefectus urbi, a highly prestigious senatorial post, and the praefectus annonae, generally a lower-ranking official with connections to the prefectural system.
Along with the provincial governors, vicarii and prefects, each of whom required scores or even hundreds of lesser officials, there were the bureaus that surrounded the person of the emperor, the so-called comitatus, or government that travelled with him. In nearest proximity was the emperor’s household staff, the cubicularii under a praepositus sacri cubiculi, or ‘head of the sacred bedchamber’. These praepositi, as well as most of their staff, were made up of eunuchs, generally from the borderlands between Rome and Persia. They supervised the imperial accounts, attended to the personal and intimate needs of the emperor and his wife, and supervised a staff of teachers, clerks and servants of various sorts, collectively known as ministeriales or curae palatiorum. The other main palatine offices dealt with the public activities in which emperors needed to engage. The magister officiorum was probably the most powerful of the bureau chiefs in the comitatus, in charge of the various scrinia required to cover the emperor’s public roles: his staff of three junior magistri – memoriae, libellorum and epistularum – handled imperial correspondence, received the appeals and petitions addressed to the emperor and the relationes (reports) of provincial administrators, and then drafted responses to them.
The bureau maintained a corps of translators for diplomatic purposes, and the magister officiorum also controlled the confidential courier system of imperial government, which was assigned to the care of men known as agentes in rebus (‘doers of things’) or magistrianoi in Greek. Numbering perhaps a thousand at any one time and with their own precise hierarchy of rank, these agentes would start their careers as messengers, but very frequently end them as highly confidential spies, secret agents or assassins, doing the sort of ad hoc duties that could not be safely regularised, but that the emperor often needed to have done in short order and with minimal publicity. Perhaps surprisingly, the magister officiorum was the only civilian official to retain a substantial military role during and after the reign of Constantine, being the titular commander of the household troop units, the scholae palatinae, though each of these had as field officer a tribune chosen by the emperor himself.
The functions of the magisterium officiorum were to some large degree duplicated by those of another palatine office, the corps of notaries. This staff was responsible for keeping track of official appointments across the length and breadth of the empire, and for issuing the commissions that came from the emperor to all officials in his service. The head of the bureau was a primicerius notariorum who kept the master list, the laterculum maius, of every imperial officer, and who issued the codicils by which officials were informed of their appointment. This required a large staff of notarii, technically clerks, but just as often in charge of all sorts of special business, sometimes working as administrators without portfolio and doing whatever the emperor needed to be done at a given time, even when it was shifty or illegal.
Though the praetorian prefects oversaw the largest sums of money circulating through the state system, Diocletian’s new financial bureaus grew throughout the reign of Constantine and thereafter, and the comites who supervised them were always senior members of the comitatus. The res privata had swallowed up the old patrimonium well before Constantine’s reign, and the comes rei privatae travelled with the senior emperor, supervising five different scrinia, or departments, dedicated to different elements in the management of imperial property, from taxation and rent to sales and escheats. The bureau of the res privata was thus represented throughout every province, with regional and provincial levels of administration.
The bureau of the sacrae largitiones (‘sacred largesses’) controlled the mints, including new Constantinian mints at Sirmium and Serdica, as well as those tetrarchic sites that continued minting. It also supervised the gold and silver mines that belonged to the state, and the fabricae, or state factories, where weapons and armour for the officer corps were made and adorned with precious metals. Finally, the bureau was the destination for all taxes collected in silver or gold: these included various tolls and harbour taxes of very long standing; the aurum tironicum (a tax that commuted a levy of military conscripts into gold); the aurum coronarium (the ‘voluntary’ donation of urban jurisdictions to an emperor at his accession and on each 5-year anniversary); the aurum oblaticium (paid by senators, on the same calendar); the collatio glebalis (an annual fee paid by senators); the collatio lustralis or chrysárgyron in Greek (a tax on all businessmen, levied every five years, originally in gold or silver, later only in gold). There were fully ten scrinia in the bureau of the comes sacrarum largitionum and, as with the res privata, these were frequently duplicated at provincial as well as palatine level.
Constantine separated the military hierarchy of the empire from the civilian once and for all, save for the anomaly of the magister officiorum and his command of palatine units. The military command, at the empire-wide level, was rather simpler than the civilian hierarchy. A distinction was gradually drawn between units of the field army, the comitatenses, and the provincial armies on the frontiers, the limitanei or ripenses. While there is some evidence for differences in the fighting quality of the two types of troops, there was definitely no fixed hierarchy of first- and second-class soldiers. The field army was commanded by two senior generals, generally serving in the emperor’s comitatus and thus known as magistri militum praesentales. The senior commander was the magister peditum praesentalis, the junior the magister equitum praesentalis, and, though one finds those titles translated into English as Master of Infantry and Master of Horse, each of them commanded forces of mixed infantry and cavalry and were generically known as magistri militum, ‘masters of soldiers’. If several emperors were ruling in an imperial college, these commands would be duplicated in each comitatus, although over time – and in parallel to the development of regional prefectures – there came to be regional command establishments for the comitatenses.
Along with the praesental magistri, there tended by the mid fourth century to be a magister per Gallias, one per Illyricum and one per Orientem, each with a more or less stable core of comitatenses that might fluctuate depending upon military conditions in the region. The permanent garrison armies on the frontiers were commanded by comites or duces with various units of limitanei at their disposal, although these were sometimes dispersed widely throughout a province and often functioned as much as policemen and frontier administrators as soldiers. A corps of protectores domestici, drawn from the privileged and well-connected children of civil servants and the military hierarchy, attended the emperor’s personal military commands and served as an officer’s training corps for the men of very diverse background who joined the late imperial officer class. These protectores domestici served under a comes domesticorum who was a senior member of the comitatus, and need to be distinguished from the regular protectores who were promoted from the ranks of the field or frontier armies late in their careers and then assigned various special supervisory tasks, often in distant provinces, as a reward for long and distinguished service. As we have noted, the palatine scholae fell outside the command of the praesental magistri militum, instead being subject to the magister officiorum. From the ranks of these special scholae, the emperor drew his personal bodyguards, who were called candidati because their uniforms were white (candidus, ‘shining’). Each palatine schola was about 500 soldiers strong, and commanded by a tribunus who was selected by the emperor himself.
Thanks to the history of Ammianus Marcellinus, a protector domesticus from an Antiochene military family who went into retirement in the mid fourth century and penned the last great Latin history to survive in any bulk, we have an unprecedented insight into how the massively complicated administrative system we have sketched in this chapter operated in practice. The Constantinian empire, with its military and civilian hierarchies, its overlapping of palatine, provincial, financial and managerial bureaus, was a world away from the Antonine world in which our story began. Then, a relatively thin layer of imperial authorities sat atop a regional and provincial landscape that was in some places very little changed from how it looked before the territory had been brought into the Roman empire. By the time of Constantine’s death, the entire empire was integrated into a system of government that functioned – often creakingly, often redundantly – irrespective of who happened to be emperor, carried on the shoulders of an imperial elite that justified its existence not by senatorial birth, but by the roles it served in perpetuating the machinery of state. Constantine had, in fact, given birth to an entirely new Roman empire.