`... after them the gods gave us Diocletian and Maximian to be our leaders, adding to these great men Galerius and Constantius, of whom the first was born to erase the ignominy of Valerian's capture, and the other to restore the Gallic provinces to the laws of Rome. Four leaders of the world, they were, strong, wise, benign, and ever generous.' - Anonymous author of the Historiae Augustae, fourth century.'
`Capitoline Zeus took pity at last on the human race and gave lordship of all the earth and the sea to godlike king Diocletian. He extinguished the memory of former griefs for any still suffering in grim bonds in a lightless place.' - Extract from a speech delivered at a festival in Oxyrhynchus in Egypt, probably in 285.2
Diocletian's violent rise to power was typical for the third century, but its sequel was very different. After decades when emperors came and went in rapid succession, he ruled for twenty years. No one had managed anything close to this since the `golden age' of the Antonines in the second century. Then, while his rule was still strong, he voluntarily resigned and retired to private life - albeit in a grand palace and surrounded by courtiers and guards. No emperor at any time had ever given up power before. Diocletian was different, and so in a number of profound ways was the empire he ruled and the way he governed it.
A striking symbol of his regime is a statue group in St Mark's Square in Venice, most probably brought there in the thirteenth century after the sack of Constantinople in the Fourth Crusade. Carved from porphyry - the purple shade that gave this stone its name was increasingly considered very appropriate for imperial statuary - it shows Diocletian and his three imperial colleagues. He ruled alone for no more than a few months before appointing a junior colleague. Later this man was given equal power, and later still two additional junior emperors were appointed so that imperial rule was shared between four men known as the tetrarchs (which simply means `the four rulers'). Designed as a corner piece, the four emperors stand in pairs, right hand clasping their colleague's shoulder and left hand holding the hilt of their own sword. Aurelian had been nicknamed `hand on sword' for his readiness to fight any opponent. The threat of force is here blatant as the tetrarchs stare outwards, searching for any challenger whether Roman or barbarian. Their clothing is military - forage caps, long-sleeved tunics, trousers and boots much like Terentius' men at Dura Europos, and breastplates. In real life they would have seemed less like ordinary soldiers or officers. Their cloaks were of military pattern, but dyed a rich purple reserved solely for emperors. Everything was made from the finest materials, and headgear, tunics and even shoes studded with gems.'
It was not just that art styles were different - rougher, heavier carving replacing the smoothness and idealised figures from the art of the early empire - so was the message. Augustus had veiled the military dictatorship he created with a facade of tradition, posing as merely the greatest servant of the state, but still belonging to the senatorial order. The veil had worn very thin over the years, but it was not until Diocletian that it was finally torn down. The tetrarchs were most certainly not `first amongst equals'. Instead, they existed on a higher level, touched by the divine and far greater than even their most senior subordinate. There was a growing trend in art to depict the emperors as physically bigger than the pygmy figures of courtiers and soldiers surrounding them. Diocletian was addressed as `lord' or `master' (dominus), sometimes even as `lord and god' (dominus et deus). Surrounded by rigid court ceremony, only a few were ever permitted to approach him. When they did so they had to prostrate themselves in obeisance. A fortunate few were permitted to kneel and kiss the hem of the emperor's robe.4
The tetrarchs were far above the people they ruled. They were also always commanders, controlling the vast armies that would be turned against any threat. Their propaganda spoke of the restoration of the empire and the world - for the Romans, the two were effectively synonymous. In one case, the suppression of a usurper was described as `restoring the light' to a province. Such boasts were not new - Aurelian had made similar claims. Certainly, they gave the empire greater stability than it had enjoyed for generations. For many modern scholars the centralisation of power, massive increase in bureaucracy and the blatantly monarchic public image of the tetrarchs were necessary to deal with the greater problems faced by the empire. A philosopher emperor like Marcus Aurelius simply could not have coped. The time for senatorial amateurism was long past and, instead, tougher rulers were needed, who simply had no time to play out a Republican charade. Leaving aside the point that such arguments have been used to justify dictators throughout the ages, this is very much an analysis based on hindsight. Diocletian's success was not inevitable, nor necessarily was the shape of the fourthcentury empire that he did so much to create. The root cause of the ills remained the internal instability producing such frequent civil wars. The tetrarchy proved only a temporary and partial break in this cycle.'
The Creation of the Tetrarchy
Diocletian was in his early forties when he was hailed as emperor. He was another equestrian army officer from one of the Danubian provinces. Stories circulated that he was born a slave, which is extremely unlikely, or that he was the son of a freedman, just like Pertinax, which is possible. Very little indeed is known about him or his career up to this point - even the fanciful biographies of the Historiae Augustae end with Numerian. Diocletian was married and had a daughter, but no son. Most emperors in the third century quickly nominated a successor, usually by naming a son or other male relative as Caesar. Many of these were infants, incapable of assisting in the task of governing the empire, but it was a promise that the new regime had a future.
Lacking a suitable relative, Diocletian selected an army officer named Maximian (fully, Aurelius Maximianus) and named him Caesar within a few months of defeating Carinus in May 285. Early in the following year Maximian was promoted to Augustus, making him equal - or very nearly equal - to Diocletian. Maximian had an infant son, but Diocletian was seeking a colleague to assist him in the present and immediate future, and was not yet concerned about the long-term succession. He needed a man he could trust, who was capable of dealing with serious problems in one region while he was busy elsewhere. There was no formal division of the empire into two halves, but Diocletian went to the east, while Maximian was sent to Gaul. They styled themselves Iovius (Jupiter-like) and Herculius (Hercules-like) respectively. Diocletian-Jupiter was the senior, father-figure - there is doubt over whether or not he actually adopted Maximian - who cared and planned for the good of the empire. Maximian-Hercules was the heroic son who travelled the world overcoming all enemies and obstacles.'
In Gaul his first task was to suppress the Bagaudae (sometimes also spelt `Bacaudae'), a group of rebels whose main strength seems to have been in the rural areas. The details and cause of this rebellion are obscure, but groups with the same name would appear in the region for several generations. It may simply have been a reflection of the decades of disorder in the area after years of civil war and barbarian raiding. Perhaps there were also wider social and economic problems, but we should be very cautious about accepting official propaganda dismissing them as mere bandits. Coins minted by their leaders claimed full imperial titles.7
Maximian seems to have quickly defeated the Bagaudae. In the meantime, he despatched an officer named Carausius to protect the Channel coasts of Gaul and Britain from seaborne raids launched by tribes like the Frisians and Saxons. Again, the Romans quickly achieved success, showing that if properly led and organised, the fleet, like the army, could still prove highly effective. However, doubts were raised about Carausius' methods and motives. It was claimed that he did deals with the raiders or that he waited until they were on the return trip before attacking them, seizing and keeping all of their plunder. The criticism may not have been justified. It was normal Roman practice to mix force with diplomacy, while it was always easier to catch raiders on their way home rather than on the way in.
Whether because he had been planning this all along or was aware that he had come under suspicion, Carausius declared himself emperor in northern Gaul, probably late in 286. The mint at Rouen was soon producing coins bearing his name, and Britain quickly declared for the usurper. Carausius was careful to acknowledge the legitimacy of Diocletian and Maximian, and seems to have hoped for their acceptance as an additional colleague. Any such overtures were rejected. Maximian was occupied for the next two years, campaigning against tribes beyond the Rhine. By 289 major preparations were underway for an expedition to Britain and a panegyric speech relished the prospect of Maximian's inevitable triumph. Similar speeches from the following years are suspiciously silent, suggesting that the campaign was a total failure. It may be that much of the fleet was lost in a storm, or perhaps Carausius was too skilful an opponent. Nevertheless, propaganda continued to dismiss him as no more than a pirate.'
Carausius continued to present himself as a colleague of Diocletian and Maximian, and does not seem to have made any aggressive moves against them. If he still had hopes of recognition, these were dashed in the spring of 293 when the tetrarchy was created with the appointment of two junior Caesars. Diocletian took Galerius Maximianus as his subordinate, while Maximian was assisted by Flavius Constantius. Both men were army officers who had probably served with them for some time. Slightly oddly, but perhaps to maintain balance or because of their age and past record, Galerius was named Herculius and Constantius became Iovius. Again, there was no formal division of territory, but in practice Maximian and Constantius ruled the western provinces and Diocletian and Galerius the east. Four colleagues meant four emperors to deal with separate problems, and it was quite rare for even the Augustus and his Caesar to operate together. It was also the clearest possible statement that only Diocletian and Maximian had the right and power to grant imperial status. No one could demand or negotiate for this and hope to succeed.
Constantius moved against Carausius almost immediately. Territory loyal to the usurper in Gaul was the first to be recaptured. Boulogne, long-established main base of the Channel Fleet (the classis Britannica), fell after a long siege. Constantius' engineers built a mole to close off the entrance of the harbour. After a few days the structure was swept away by the sea, but it had lasted long enough to isolate the garrison and convince them to surrender. Carausius was murdered around this time by one of his own officials, a man named Allectus. Historians have often connected this plot with the blow to his prestige when Boulogne was lost, but this remains conjectural. Allectus lasted for three years before Constantius invaded Britain and killed him in battle. The actual fighting may have been done by one of his officers, but coins portrayed Constantius' triumphal entry into Londinium (modern London). Between them the two `British' usurpers had ruled for a decade.'
A briefer, though still serious, challenge to the tetrarchs came from Egypt in 297, when a man named Lucius Domitius Domitianus declared himself emperor. Diocletian put down this rebellion, supervising the siege of Alexandria in person. When his men stormed the place, he is said to have commanded them to kill until the blood in the streets came up to the knees of his horse. Fortunately for the Alexandrians, the horse stumbled and fell as it came into the city. The killing was halted and the grateful population subsequently set up a statue of the horse. This romantic story should not conceal the brutality with which any challenge to the tetrarchy was met.'°
The bond between the four emperors was strengthened by marriage ties, Constantius and Galerius marrying Maximian's and Diocletian's daughters respectively. In addition, each of the Augusti adopted his Caesar. Unity was stressed at every turn. Edicts were issued in the name of all four emperors, whichever was actually the source. In most cases only Diocletian issued rulings or decrees applicable throughout the empire. He was the man who had appointed his colleagues, and his was always the dominant personality. When Galerius suffered a reverse against the Persians, Diocletian is supposed to have made his Caesar run alongside his chariot, still wearing his full regalia."
The Growth of Government
Four emperors meant four men with supreme authority to command and dispense justice in four different regions simultaneously. Ideally, this would prevent regions from feeling neglected and so inclined to support usurpers who promised to deal with local problems and promote local men. Any challenger would have to defeat more than one established emperor at the head of an army. The refusal to negotiate with Carausius demonstrated that no one would be allowed to force their way into power and retain it in the long run. The tetrarchy worked as long as the imperial colleagues remained firm in their alliance with each other and none suffered a cataclysmic defeat. This was not really a product of the system itself, but had far more to do with the competence of the tetrarchs. Even more important was the forceful personality of Diocletian, who imposed solidarity on his colleagues.
Diocletian himself may only have visited Rome once during his reign, when he chose to celebrate the twentieth anniversary of his acclamation in the city. Rome remained a powerful symbol and its population continued to be pampered with festivals, games and free doles. Diocletian ordered the construction of a massive bath complex, larger than any of the earlier public baths. There was also considerable building work in the Forum, repairing and remodelling after a major fire had swept through this part of the City during Carinus' reign. The Curia (Senate House) visited by so many tourists today is essentially a tetrachic building, restored in the twentieth century some thirteen hundred years after it had become the Church of St Hadrian. Politically and strategically, neither the Senate nor Rome were now of more than marginal importance to the empire and its rulers."
When any of the tetrarchs were in Italy they were far more likely to be found in the north at Milan, more conveniently placed to move east into Illyria, or north-west into Gaul. The cities most often chosen for imperial residences give an indication of the tetrarchs' priorities - Trier on the Rhine, Sirmium near the Danube, Antioch in Syria and Nicomedia in Bithynia. All acquired palaces, usually with an adjacent circus, and other grand buildings. Trier's prosperity contrasted with the harder times faced by other communities in the area. It would be wrong to speak of any of these places as permanent capitals as each of the tetrarchs moved frequently. All went to war at various times, and even when they were not actually on campaign they tended to move from city to city. The many decrees and legal rulings of Diocletian preserved in later collections of Roman law were issued from a huge range of different places. The court and, in a real sense, the capital were wherever the emperor happened to be at the time."
Emperors did not travel or live alone. Each of the tetrarchs was protected by thousands of soldiers from guard units. These had grown in number in recent decades so that the praetorians were relegated to a comparatively minor role as little more than the garrison of Rome. Diocletian was the commander of one of these new guard regiments when he was proclaimed emperor. If there was a prospect of actual campaigning - frequently a real possibility when the emperor was in frontier zones - then the guards would be supplemented by more troops. The trend for emperors to keep strong military forces at their immediate disposal had grown since Septimius Severus had increased the numbers of soldiers in and around Rome. One hostile source claimed that under Diocletian the size of the army quadrupled because each of the tetrarchs wanted as many soldiers as their colleagues. This was certainly a huge exaggeration. There were many more units in the army, but each was probably smaller in size than had been the case in earlier periods. Whether or not there was still an overall increase, it is clear that each of the tetrarchs controlled substantial numbers of troops. Superior military force was the ultimate guarantee of imperial power.14
Soldiers guarded an emperor, but he could not govern through them. Whatever the size of the army under Diocletian, it is absolutely certain that there had been a massive rise in the number of civil officials. Augustus and his successors for two centuries had run the empire with the tiniest of bureaucracies. Its origins and its basic nature evolved from the household of a Republican senator - the slaves, freedmen and sometimes also friends who helped run his private business and assisted him when he held a public magistracy. The staffs of provincial governors were similar, but smaller, and might be supplemented in military provinces by seconded soldiers. This system did not change in any fundamental way during the first and second centuries. The size of the imperial household grew a little and its organisation became a little more formal. The unpopularity amongst the elite of powerful imperial freedmen led to some reliance on men of higher social background - usually equestrians - in the more senior public roles. A huge amount of day-to-day administration was devolved to local communities, most especially cities, but also villages or tribes where these did not exist. Depending on who is included in the figure, the `bureaucrats' of the imperial government numbered in hundreds, or at the very most just over a thousand.
By the beginning of the fourth century this total had soared to somewhere between 30,000 and 35,000 - an orator once described the hordes of minor officials as `more numerous than flies on sheep in springtime'. The growth of bureaucracy was gradual, but it was greatly accelerated under Diocletian. Part of this was simply the natural result of multiplying the number of emperors. Each now had to have a court and administrative departments - for instance, to handle justice, taxation and other forms of revenue, correspondence in both Latin and Greek, controlling provincial governors and maintaining the army. Many offices were simply duplicated. Both Diocletian and Maximian had a praetorian prefect, who had lost virtually all his military responsibilities and was effectively an administrator. The Caesars Constantius and Galerius did not, but did have their own officials and heads for all the other depart- ments.15
The Severans had split up the great military provinces to prevent any governor becoming too powerful and so a potential threat. The tendency to divide provinces into smaller regions continued on and off throughout the third century. By the time Diocletian became emperor there were about fifty provinces - roughly a third more than in the days of Marcus Aurelius. Diocletian then `sliced up the provinces into little pieces' according to one particularly critical source, doubling their number. This was not primarily about protecting himself from usurpers - the great military provinces with garrisons of 30,000-40,000 men had long since gone. Instead, it had far more to do with control and taxation."
There were now many more governors, each in charge of a much smaller area than would have been typical in the first or second century. Italy and a handful of other provinces of no military importance were governed by senators known as correctores, but everywhere else the governors were equestrians. By the end of the reign even these had lost virtually all authority over troops. In a radical break from a very old Roman tradition, only emperors still combined civil and military power. Apart from general administration, governors had a particularly important role in overseeing justice and finance in their provinces.'?
There were more provinces and more governors. Each may well have had a larger staff than was typical in earlier centuries. The result was a huge increase in the number of imperial representatives in each region (even if these would still seem small compared to the bureaucracies of modern states). In one sense this made it harder for the emperors to keep a close eye on what their agents were doing. Provinces were therefore grouped together into larger units known as dioceses. Eventually there were twelve of these - Italy, Spain, the Gauls, Viennensis, Britain, Africa, the Pannonias, the Moesias, the Thraces, Asiana, Pontica and Oriens. Unofficially, Italy was effectively divided into two. In charge of each diocese was a subordinate of the praetorian prefect. These men were called vicarii (from which we get the word `vicar') because they acted in the place of the prefect. It was not a rigid hierarchy. Emperors frequently chose to deal directly with a governor without going through the vicarius for that diocese. Similarly, they might deal with a vicarius without consulting his praetorian prefect. On occasions, subordinates could also choose to bypass their superiors and appeal to the emperor or prefect directly."
The command structure of the army was entirely separate. The frontier regions and other areas that required a strong military presence were divided up into districts. All the troops stationed in this district were placed under the command of an officer known as a dux (duke, pl. duces). These military zones did not correspond to provincial boundaries and usually included territory from two or more provinces. Other troops not confined to any fixed garrison were commanded by different officers whose rank was comes (count, pl. comites). In the past the same term had applied to companions - usually senators - who accompanied the emperor on an expedition. A distinction emerged early in the fourth century between troops likely to serve under the command of an emperor, who became known as the comitatenses, and the troops of the duces, who became known as the limitanei."
Both soldiers and administrators were servants of the emperors. The bureaucrats had ranks and uniforms all clearly derived from the army. They wore military caps, tunics and the belt with its large circular buckle from which a soldier would suspend his sword's scabbard. Time in any government post was described as militia (military service), and it became common for members of a department to be nominally enrolled in a legion or other military unit that had long since ceased to exist. Yet in spite of this military facade, the army and civil service were kept utterly distinct. Men pursued a career in one or the other, but did not switch between the two. Over time a huge number of different grades were created within civilian departments, creating a hierarchy even more complicated than the rank structure of the army. Instead of recruiting men from specific social groups, status tended to become tied to rank, so that senior posts brought with them promotion to senatorial status. Equestrians enjoyed a virtual monopoly of the higher ranks in the army and civil service, but this led to the creation of several different grades within the order. Again, over time the grade was gained by holding a post and was not a prerequisite for it.2O
Aspirations and Reality
Government had become a lot bigger. It was certainly more visible and more likely that ordinary citizens would come into greater contact with it during their lives. In theory at least, the development of a much larger bureaucratic machine could have allowed the emperors to run the empire more efficiently. Caracalla's universal grant of citizenship had made most of the population of the empire subject to Roman law, something imperfectly understood in many regions and so only gradually adopted. In the long run this inevitably placed a greater strain on the provincial governors and their small number of subordinates with the power and ability to act as a judge. More governors with enlarged staffs were, in part, intended to deal with this increased business.
Yet the first concern of all emperors was revenue. All knew that they could not stay in power unless they were able to maintain the army and meet the smaller, but still dramatically increased cost of the enlarged bureaucracy. Emperors had significant private funds, for they were the largest landowners in the Roman world. Imperial estates had begun simply as the private property of Augustus and his successors. They were augmented by conquests and the confiscation of property from the condemned. Since the end of one dynasty usually meant that there were no heirs, the imperial estates continued to grow as lines died out and new emperors came to power. A distinct section of the department in charge of revenue administered the income from these lands.
On their own, the imperial estates provided only a fraction of the income needed by emperors. The bulk had always come from taxation, mainly in cash, but always including some paid in goods - usually agricultural produce. Whatever the impact of inflation in the third century on the wider population, it had drastically reduced the real value of taxes. Many of these were levied at fixed rates that had remained static for centuries. Similarly, the salaries paid to those in imperial service - soldiers and civilians alike - did not increase dramatically after the early third century and had fallen in their purchasing power."
Diocletian embarked upon a fundamental reorganisation of the taxation and levy system. Communities were assessed in terms of two basic units, measuring both land and labour force. Land was divided into iugera, the size of which varied according to the type of farming possible there and its expected productivity. The second unit was the head count of the adult population available to work the land. From these two units the obligation to the government of a region was established. Setting up the system may have taken a decade or so, as parties of assessors travelled to each province. There were many local variations - for instance, in the age of those counted and whether women were included along with men, as well as the inevitably subjective judgements of land quality. Even so, a uniform taxation system was imposed throughout the entire empire."
In the majority of cases tax was levied in the form of produce, protecting the system from inflation. Much of this was used to supply the army directly, and anything not needed could be sold at the current market rate. In addition, pay for soldiers and civil servants became largely based on rations of food, fodder and other commodities. (This was not true of the donatives issued regularly to commemorate the accession dates of the emperors, which continued to be paid in gold.) What was not needed could be sold or exchanged for what was. Later in the fourth century parts of the system became somewhat artificial as many of the rations were commuted into cash. There is no evidence that this was the case at the beginning, but it is equally unclear how the system functioned in every detail. As an example, how would a clerk in one of the civil departments dispose of unwanted fodder or grain, since there would usually be so many other members of the court trying to sell off their excess at the same time and in the same place? Perhaps there were agents who acted for a group of imperial employees and divided the produce, but it may be that the government did not actually go to the laborious task of delivering each ration to each recipient and instead paid them an equivalent based on an assessment of the going rate.
Diocletian also embarked on a thorough reform of the currency. Gold and silver denominations minted to a reasonably high standard were created. There was also a copper coin with a thin wash of silver known as the nummus which was intended for much day-to-day exchange. As part of the multiplication of government more mints were created, producing coins for the immediate use of army and administration in that area. Inflation may have slowed, but did not stop. In 301 Diocletian issued an edict intended to regulate the sale price of goods. Inscriptions bearing parts of the text of this have been found from sites in a number of eastern provinces, but it does not seem to have been circulated or enforced in the western provinces under Maximian."
A great range of items was included. A measure (the Roman unit known as a modius = a quarter bushel) of wheat cost i0o denarii, of barley or rye 6o denarii, while the same quantity of oats was worth only 3o denarii. Wine varied from the high quality- for instance, the Falernian wine praised by the poet Horace three centuries earlier - at 3o denarii to the cheapest at a mere 8 denarii. A pound of pork was 12 denarii, while the same weight of high-quality fattened gooseflesh was no less than 200 denarii. Apart from foodstuffs many other goods, from spices to clothing, were listed. Also included were proper rates of pay for many different professions. Teachers were paid per pupil, tailors for each specific job they did and labourers by the day. All values were in denarii, and although it had been a long time since anyone had minted a single denarius coin it still remained the basic unit for currency. A law some months earlier had set the value of a silver coin at ioo denarii and the silver-washed copper nummus at 25 and 4 denarii depending on its size.14
The only literary source to mention the price edict derides it as an utter failure, ignored by merchants who knew that they could charge more for their goods. Papyri from Egypt do suggest that prices soon rose far beyond the supposed maximums established by the emperor. As far as we can tell it was abandoned fairly quickly, but at least one copy was maintained long enough for a few of the prices to be altered. In his long introduction to the edict, Diocletian reminded his audience of the stability and success his rule had brought, and claimed to be expressly concerned that his brave soldiers were being overcharged. There may also have been a desire to set rates at which the state would pay for goods and services regardless of the market price.
Diocletian's government lacked the machinery to enforce such a rigid pricing system on a day-to-day basis. Perhaps the most striking thing about the edict was its ambition - even if it was economically naive. Combined with the objective of profound change is the highly moral rhetoric. Talk of `the peaceful state of the world' now that the `seething ravages of barbarians peoples' have been restrained by great effort, is followed by outrage at a new evil attacking the soldiers. `There burns a raging greed, which hastens to its own growth and increase without respect for human kind.' A little later the emperor compared this greed to a religion. The tone is typical of the other legislative activity of the tetrarchs and of their recorded rescripts - replies issued to legal questions and appeals sent to the emperor. The sense of outrage was accompanied by savage and often inventively cruel punishments.26
Born around 240, Diocletian was far more successful than any of the other emperors in his own lifetime, or indeed for a generation before that. Having lived through decades of disorder and chaos, there was a good deal of truth in the tetrarchs' claims to have brought peace and restoration. Diocletian may genuinely have believed his own propaganda. He certainly felt that the best way to deal with the empire's problems was to impose strong central control. This was not a new idea. Bureaucracy had been growing in the last decades. The turnover of emperors was so rapid that officials, especially those of middle rank who were less likely to be purged when a regime changed, provided the most stable element in government. Diocletian stayed in power longer than his recent predecessors, his strength increasing with each passing year. He was therefore able to take much further the trend towards centralised government.
However, it was still a gradual process. He may have had some longterm plans from early in his reign, even if these ideas were developed or replaced over the years. The creation of new provinces and the growth of government departments were not instant. The tax reforms were probably not completely functioning until near the end of his reign. The new institutions of government helped to strengthen his position, but they were not the cause of his success and longevity. Their effectiveness also depended to a great extent on his own drive, political ability and sense of purpose. Closely supervised and led by carefully chosen and loyal praetorian prefects and governors, the new bureaucracy allowed the emperor to have far more impact on life in the provinces. The scope and tone of his decrees suggest that Diocletian believed that he could and should regulate anything brought to his attention.27
The emperors were supreme and ruled through a vast number of officials who had power and status only because they were imperial representatives. The tetrarchs themselves were far above them in dignity and authority. They were distant figures, closely guarded at all times. The slaves who cared for them - now increasingly often eunuchs - became powerful. The senior servants, like the Grand Chamberlain (praepositus sacri cubiculi), Superintendent of the Bedchamber (primicerius sacri cubiculi), and the Chief Steward (castrensis sacri palatini), in due course were ranked higher than the vast bulk of the nobility. When emperors resided in cities they did so in splendour. When they travelled they were surrounded by thousands of troops, bureaucrats and attendants, as well as the hundreds or even thousands more people who had come to the court in the hope of presenting a petition. From Diocletian onwards it was harder to approach emperors, which did at least mean it was also far more difficult to murder them. Some sources and historians have seen this new ceremonial at court as inspired by the authoritarian rule of the Persian kings. This is deeply questionable, and we should remember that there was a very old rhetoric stretching back to Herodotus presenting kings and most especially eastern monarchs like the Persians as the epitome of tyranny. It is far more likely that Diocletian enjoyed ceremony and felt it added to the majesty of his rule. Anything likely to instil obedience in his subjects and deter rebellion was to be welcomed.z8
The success of Diocletian and his imperial colleagues emphasised the still massive power of the Roman empire. Given a period of relative peace and stability, and most of all a time of continuity in government, the Romans re-established a degree of dominance on their frontiers. Diocletian was able to raise more tax revenue than had been possible for more than a generation, which in turn funded the military activity. New forts were built and old ones repaired. Generally the new bases were smaller, but had higher and thicker walls than earlier forts and fortresses. Victories were won over barbarian tribes, treaties negotiated from a position of strength and, as the reign wore on, fear of Roman might grew once more. Potential raiders became more cautious. There were still attacks, but they were fewer and more often caught and defeated. The situation had improved, but it would have taken far longer to undo all the damage of past defeats.'9
Sassanid Persia became aggressive again early on in the reign. After a renewed period of civil war - his predecessor only lasted a few months - in 293 or 294 Narses came to the throne. Victor in a civil war, he was both a strong military leader and deeply insecure. A war with Rome offered the prospect of glory and uniting his subjects against a foreign enemy. The Persians attacked, most probably raiding into the Roman provinces in 296. Galerius was sent against them and may well have suffered a reverse - this is the context of the story about Diocletian making his Caesar run alongside his chariot (see page 162). With greater resources, including troops transferred from other regions, Galerius renewed the war and this time won a spectacular victory. Narses' camp was captured, and along with it his harem and much of his household. Ctesiphon was once again taken by a Roman army, probably in 297 or 298. Early in the following year a peace treaty was imposed on the Persian king, who gave up some territory and acknowledged Roman supremacy over a number of independent border kingdoms including Armenia. The frontier between the two powers was set at the Tigris, and the city of Nisibis - now back in Roman hands - was established as the only legal place for merchants to pass between the two empires. This helped each side to control the bulk of contact, as well as to tax the trade passing between the empires. The peace, which was very much to Rome's advantage, lasted for forty years.3°
Diocletian was one of the most important emperors in Roman history. Just like Augustus, he came to power after a long period of civil war and disorder, and both profoundly changed the state through their reforms. Neither acted in a vacuum, but developed already existing trends in public life almost as much as they innovated. Perhaps more than anyone else, Diocletian established the shape of the fourth-century empire and in doing so removed most of the last traces of the Augustan regime. The military dictatorship was no longer veiled but blatant. The tetrarchy was effective because of the strength and solidarity of its members. Ultimately, its greatest test was the question of succession. In this respect, however, the tetrarchy failed.