The Roman senate had few powers other than nominal ones. But its six hundred members were very rich men. They also included the senior generals, whose support the emperor needed; and senators enjoyed great prestige among all classes.17
Originally they had all been Italians, and under Vespasian (AD 69–79) over 80% were still of Italian origin. But Trajan (98–117), himself from Spain, admitted provincials as often as Italians; and soon after his death Italy provided not much more than half the senate’s total strength, with Africans now becoming members alongside Gauls and Spaniards. During the latter part of the second century, in spite of Marcus’ efforts to keep the senate racially pure,18 there was a continuing shift of emphasis from westerners to Syrians and Asians and other orientals, who had provided only a small contribution until now.
Under Septimius and Caracalla these tendencies increased. Out of 479 of their senators whose origins are known, 204 were Italians, representing only just over 40% of the total and including very few survivors of the 43 patrician families that had existed a century earlier. These Severan 479 also included 41 members from the western provinces, 72 from Africa, 5 from the Illyrian region, and 157 from the east.19 Throughout the third century, Italian membership remained static at the same percentage, and the proportion of easterners stayed at a figure rather over 30%.20 But the proportion of westerners among provincial senators had declined from 70% under Vespasian to 13.6% at the end of the third century. The relatively uneducated Danubian populations, in spite of their immense contributions to the army and to the list of emperors, continued to provide only a few members to the senate.
The normal attitude of rulers to that body was a blend of conciliation and suspicion. The latter feeling showed itself in arrangements to keep certain key posts in the hands of non-senators. For example, although provincial governorships and military commands always went to members of the senate, Augustus had instead entrusted not only the governorship of the immensely rich new province of Egypt but the command of his praetorian guard to the knights or equestrian order (equites), the class of society based on property qualifications next below those of senators. During the second century the knights, who normally reached that rank by holding three officer posts in the army, often served as advisers attached to high senatorial officials and represented them as deputies.
Under the Severan dynasty this practice was extended to provincial governorships, which were kept vacant and occupied by knights in an acting capacity. Septimius, like some of his first century predecessors, was unfriendly to the senate, because so many of its members had supported his enemies in the civil wars; and its privileges must have seemed pointless in an age when there was a growing imperial civil service. Septimius eliminated the senators he disliked, and in their place drafted new members from among the knights. Many of these had reached knightly status from N.C.O. and private soldier rank.21 Septimius further weakened the influence of senatorial traditionalism by selecting knights to occupy the recently established governorship of Mesopotamia, and the command of his newly mobilised legions.
This break-up of established patterns became clearly perceptible when the army created the first emperor who was not a senator but a knight, a lawyer from Mauretania named Macrinus (217–18). This was a severe shock to conservatives such as the Greek senator and historian Dio Cassius. Writing either just before or after Macrinus’ reign,22 Dio makes Augustus’ adviser Maecenas, ostensibly debating against the more democratic Agrippa, advocate a stable, centralised, sharply graded society, opposed to change since this can only bring dislocation. Officials, believed Dio who was himself a Bithynian, should be taken from all parts of the empire, but only from the old-established citizens – a trained and élite ruling class which the emperor should take into partnership so as to prevent political interference by the proletariat.23 The emperor, Maecenas is made to add, may regard consultation of the senate as a formality, but all the same he should not omit to seek its views, and he should guarantee the dignity and personal safety of senators.
Admirers of Severus Alexander (222–35), under whom Dio held high office, said that this emperor revived senatorial powers. But his apparent deference was due to weakness rather than liberalism, and in any case did not alter inexorable trends. Dio urged that senators should not be deprived of military commands, but the tendency in this direction was maintained.24 Very soon knights are found as frontier commanders at Dura and in Tripolitania, and from the time of Gallienus, though he himself came from a distinguished senatorial family, military commands do not seem to have gone to any senators but were all held by knights. The senate now only provided the governors for ungarrisoned provinces and the occupants of certain administrative and judicial posts in Rome and Italy.25 These developments formed part of a growing separation between civil government and military command. Each emperor wanted to give the big military appointments to experts – and experts who owed their positions to himself alone, and did not feel bound to any other loyalty.
At this period personified figures of the senate, which had occasionally appeared on the Roman coinage, disappeared for a time, but the custom was revived a few years later when that institution, reverting to an ancient and obsolete custom, took the lead in placing the emperor Tacitus on the throne (275–6). The army, which had usually taken such imperial nominations upon itself (p.13), actually encouraged this initiative. For although the senate no longer contained the most important officers and comprised few of the Illyrians who dominated the military scene, its interests and those of the army were drawing together. The senate’s membership included the great landowners who collaborated with the army to keep the peasants in tax-paying subjection. Besides, this was an age when symbolic and abstract values often seemed more important than reality, and, as the senate’s power declined, military men venerated this ancient gathering more and more as the mirror of eternal Rome (p. 164). The senatorial nominee Tacitus did not last long, but it was in the same spirit that Diocletian, although he gave members little employment, repeated formal honours to the senate as an expression of the united commonwealth; and its Genius is portrayed on his monument in the Roman forum.
The separation of the civil government from the military command was completed by Constantine. But by now, if not before, the old division between senators and knights was abolished altogether. In a senate of greatly enlarged dimensions26 – duplicated before long at Constantinople – the two classes merged into a single grade of administrative officials and powerful landowners, of whom Constantine made abundant use. The old hierarchy had finally given way to a different and almost medieval system. Moreover, the same emperor sought to increase the number of his own devoted supporters by creating a new order of nobility, the Imperial Companions (comites). There had always been ‘friends of the emperor’, enjoying privileges of personal association and etiquette; they were all senators until the time of Septimius, who had drawn them from the knights as well. But Constantine made these friends into official companions occupying the position at the emperor’s pleasure or for life. They were divided into three grades, and selected members served on the imperial council.
That council, an inner advisory committee far closer to the emperor than the senate, originated from the traditional Roman practice by which an official of the Republic, in making a decision, was accustomed to choose a group of assessors or friends and take advice from them. Augustus had developed this Republican custom, and his councillors prepared the business of the senate. But the second century AD brought the council wider powers, because the emperors, being now practically the only source of law (p. 67), needed legislative advice: they also used their council as a judicial private court. Hadrian’s council members already included a professional nucleus of experts, and by Severan times the policy-making departmental heads of the civil service were dominant in its deliberations, with the praetorian prefect as deputy chairman (p. 76).
Septimius allowed his council considerable freedom, but his ill-tempered son Caracalla was impatient of advice. Nevertheless, as more and more branches of the government came under imperial control, this committee, with the approval even of Dio Cassius, reached the height of its influence, playing a dominant part in the transformation of the Roman world. The outstanding jurists of the day were now among its members (p. 77) – in Severus Alexander’s council of seventy members they were twenty strong, the balance being provided by senators and civil servants. Their business had become so formalised that the written views of all members were now recorded. An emperor such as Maximinus 1 (235–8), whose autocratic tendencies were limited by his poor knowledge of Latin, depended on them to a considerable extent; though during the even tougher times that followed we do not hear a great deal about the institution.
Diocletian’s council, however, was an influential advisory cabinet. Senior civil servants were prominent members, and Constantine’s further reorganisation of the body under the name of consistorium (because the members no longer sat but stood in the emperor’s presence) was marked by the triumph of the civil service chiefs, who were subject only to the emperor in their exercise of judicial, executive and legislative control.
The imperial civil service originally consisted of slaves and freedmen, and eventually knights, from whom the emperor, in order to supplement the old Republican state machinery, had drawn his household staff and relatively small central secretariats and accountancy departments, and the financial staffs of his agents in the provinces. Second-century emperors and especially Septimius, who derived his major officials from Syria, Asia Minor and his native Africa, expanded this imperial bureaucracy, which now increasingly assumed the character of a separate organisation. The chaotic period that followed, when few emperors were able to establish themselves firmly, gave the administrative machinery an independent strength of its own,27 which rulers such as Gallienus, unwilling to make the senate a pillar of their régimes, gladly recognised.
Under Diocletian this autonomous civil service became enormous, absorbing a substantial part of the entire middle class of the empire. Diocletian needed a much more elaborate organisation so as to levy the men and supplies necessary for his enlarged army (p. 52); indeed, in order to stress its subordination to the emperor, the governmental administration itself took on a military shape. And so the massive civil service pursued its bureaucratic, ill-paid, corrupt, and partly but not wholly inefficient career through the ensuing centuries,28 becoming the essential element in the structure which held the Byzantine empire together.
A major change was also introduced in provincial administration. Diocletian, who had himself served as a governor, more than doubled the number of provinces, so that the men in charge of these relatively small areas, completely separated from military commands, should have little opportunity to revolt and should concentrate on jurisdiction and finance (p. 20). However, Diocletian also innovated by grouping these provinces, now a hundred in number, into thirteen major units or dioceses. These big territories, pointing the way to national groupings of the future, comprised the orient (Syria, Mesopotamia, Palestine, Egypt), two dioceses in Asia Minor (Asiana and Pontica), three in the Balkans (Moesia, Thrace and Pannonia), one each in north and south Italy, Africa, Spain, north and south Gaul, and Britain.29 The dioceses were for a time administered by governors-general (vicarii) under the praetorian prefects.30 But in most areas, between the times of Diocletian and Constantine, governors-general faded out in favour of direct contact between prefects and provincial governors.
The praetorian prefects had originally been commanders of the emperor’s personal bodyguard. In the early empire these functionaries, holding office singly or more often sharing their powers between two or occasionally three colleagues, had played vital parts in bringing emperors to the throne and keeping them there. Although this sort of crisis temporarily became more infrequent during the more stable second century, prefects continued to fulfil an increasingly important role as military deputies of the emperor, acting as his quartermasters-general and often performing the duties of chief of staff on campaigns.
Rulers had not interpreted the prefecture as anything like a vice–emperorship, preferring to keep exalted positions of that sort, if they were needed, within their own families. The first prefect given an opportunity to exploit such wider possibilities on an extensive scale was Perennis, who rose from being joint holder of the office under Marcus Aurelius to its sole occupancy under Commodus. Perennis fell (185), but his enhanced authority was soon afterwards inherited by the emperor’s chamberlain, a Phrygian freedman called Cleander. The next prefect, Laetus, played a leading part in the murder of two emperors and was executed for suspected treachery by the next (193).31 Septimius’ African compatriot Plautianus reached giddy eminence by marrying his daughter to the emperor’s son Caracalla, but his new son-in-law shortly afterwards arranged his downfall (205).
By now the prefects were deputy-chairmen of the imperial council. They were also given the function of raising the taxes in kind on which the army depended for its supplies, so that the prefecture, expanding far beyond its original functions, had become an all-important ministry of finance (pp. 50–52). Moreover, Septimius normally delegated to his prefects the hearing of appeals from provincial governors – which were particularly frequent as a result of the civil wars – and entrusted them with Italian jurisdiction that standing jury-courts had undertaken before.32 Because of this increasingly important legal aspect of the prefects’ powers, there now followed a period during which the greatest jurists of the age, and perhaps of any age, served in the place (or as colleagues) of the generals who usually occupied the office. Papinian and Ulpian became praetorian prefects (p. 79), and the Roman government was in the hands of lawyers. But this phase, inaugurated by Septimius and continued by Caracalla, was not very successful owing to the difficulty experienced by lawyers in controlling the guardsmen, and after two decades prefects were army men again. Dio Cassius had been nervous that these officials would win too much power in the military sphere,33 and indeed Gordian III, himself too young to lead the imperial forces, not only married the daughter of his prefect but entrusted him with the supreme wartime command (242). Fortunately for him this official Timesitheus was not only an able general and administrator but a man of disinterested loyalty. It is doubtful if the same can be said of Philip, who succeeded first to the prefecture and then to the imperial throne. When Valerian and Gallienus divided the empire between them, each had his own prefect.
The praetorian prefect, like other military administrators, had always possessed a staff of officials and clerks seconded from the army, and under Diocletian, as part of a general militarisation of the government, this infiltration by soldiers increased. By now the prefects, who were still two in number, had become grand viziers with a huge separate organisation responsible for collecting the taxes in kind and cash. They also maintained the roads and postal service and arms factories, and supervised the administration of the provinces, first through their deputies and later direct.
But Constantine decided that such a concentration of powers in the hands of prefects was too large to be efficient or safe. From now on, although retaining many duties including the supply of the army’s recruits, weapons and rations, they lost their functions of military command, which passed to the new Masters of the Horse and Foot. Moreover when Constantine, at the end of his reign, divided the empire among the younger generation, the praetorian prefecture was likewise split into separate offices at the disposal of each of the heirs apparent.34