The Emperor who both saved and destroyed the Roman empire

Coin of Diocletian

This gold coin of Diocletian gives a good impression of the stern autocrat

At the end of the 3rd and the beginning of the 4th centuries there were two great emperors – Diocletian (284 – 305) and Constantine (306 – 337). Both were great, but were they good? They both realised that the chaos of the later 3rd century meant that drastic reorganisation was needed, and they carried out this drastic reorganisation so successfully that Rome continued to thrive throughout the 4th century. But what was the downside?

Could it not be said that the reforms of Diocletian and Constantine mark the crucial change when the civilisation of Rome collapsed into barbarism and that many of the features that made Rome so uniquely attractive were replaced by features more at home in the great barbarian empires of the east?

Diocletian, like most of the emperors in the late 3rd century, came from Dalmatia (Croatia): he was born around 244 at Salona, near modern Split, where indeed he retired. Little is known of his early career and his rise to power; one suspects that he took care when Emperor to draw a veil over his early life, but he was clearly a first rate soldier and a charismatic leader. On the death of his predecessor Carinus, he was chosen by the soldiers to be emperor, murdering his only possible rival Aper on the way. His career was one of fighting and of numerous constitutional changes.

This statue of the four tetrarchs embracing each other in brotherly affection was originally set up in Constantinople. However in the fourth crusade in 1204 it was carried off to Venice where it can still be seen in St Mark’s Cathedral.

It is difficult to know where to begin in describing his many reforms. Perhaps the most momentous was that he divided the rule of the empire into four. There were to be two chief emperors who were called Augusti and there were two sub-emperors who were called Caesars. He himself became the Augustus of the East and made his headquarters in Nicomedia, not far from Constantinople, while his subordinate Caesar, Galerius, took control of the Illyrian provinces. In the West, Maximian became Emperor while Constantius Chlorus became Caesar. Indeed it was Constantine, the son of Constantius, who was to be the second reforming emperor who in many ways completed these reforms.

Diocletian's Palace at Split

In AD 305, Diocletian retired to this splendid palace he had built near his birthplace at Split, on the coast of Croatia. This reconstruction drawing by the French town planner Ernest Hebrard was published in 1912. Note the roof gardens where Diocletian grew his cabbages. 

He made elaborate arrangements for retirement.  He built a great fortified palace  for himself at Split on the coast of Croatia near his birth place of Salona. Today much of the palace still survives at the heart of the modern town, now the second largest town in Croatia.  And it was here that he did indeed retire, the only Roman Emperor who formally retired, and spent his days tending his cabbage patch.

But though we tend to think of Diocletian as essentially an administrative reformer, he was also an all round emperor.  As a general he was extremely successful, fighting wars against the Sarmatians and the Alemanni and putting down a rebellion in Egypt, while one of his caesars, Constantius, the father of the later emperor Constantine, invaded Britain which had broken away to become independent under Carausius, but was now successfully brought back within the empire.  However his biggest success was in the war against Persia where he successfully attacked their capital and more importantly made a long lasting and favourable peace.

But his biggest changes were in administration. With the provinces, there was always the problem that the provincial governors were in command of substantial armies and might therefore set themselves up as emperor, so he decided to break the provinces up.  This had already been happening before, indeed Britain had been divided into two, but Britain was now divided into four provinces, and overall around fifty provinces were divided into around a hundred provinces, though these were organised into twelve dioceses.  And the governorship was also divided up and the governor now called a praesides was responsible for justice and taxation, while the military command was organised separately under leaders called duces – who survive as the modern duke.

But the major changes came in taxation.  Here the big problem is that as taxes were fixed by a given amount, inflation meant that the value of taxation steadily decreased.  Constant inflation meant that taxation was raising an ever smaller amount of real value.  How could it be replaced?

The answer is to revert to the financial arrangements of the pre-money or non-money economy and to replace money tax by with a tax in kind, which is just what happened in Diocletian’s reforms. The old taxes still continued to be levied: there was the poll tax and the old land tax known as tribute, but both were overshadowed by a new tax called the annona. Annona was originally a goddess of the harvest, and in times of crisis, a special emergency tax would be levied to feed the army. But during the third century, such emergency taxes were levied ever more frequently and ever more heavily: with inflation, the soldier’s salary no longer covered the cost of food, so they began to receive an allowance of food instead. This practice was systematically organised by Diocletian. The supply of provisions, — consisting of corn, oil, wine, salt, pork, and mutton — necessary to feed a soldier for a year, was calculated and was called the annona. In the course of the fourth century, the principle was extended and even civil officials received salaries in kind.

A census was taken to assess the basis on which the tax was levied. This was in places extraordinarily complex. In Syria for instance the land tax was assessed in various bands, with three different bands for arable, and quite separate bands for vineyards and olive groves. It was assessed on the basis of a iuga, which was the amount of produce that one man and his family could be expected to produce.

The census became the basis on which peasants became tied to the land. In a document from Egypt it is laid down that for the purposes of this census every body must return to their home village. But once the census had established the taxation to be levied, as the produce of so many people, then there was a tendency to insist that once one was recorded on a census, that was one’s legal place of residence. One could not move away from it, and furthermore your children had to continue to cultivate the land and provide the taxes. This completely breaks with the right of migration that had been granted so many years ago by the ius Latinum, the Latin right.

Inside Diocletian’s Palace, as seen today

This is the classic definition of serfdom. A serf is someone tied to the soil and who cannot move away. It is sometimes remarked that communist Russia remained a serf society because permission was needed for travel and one could not move away from your registered place of residence. Certainly in 19th century Russia, this was very much the basis of serfdom and all its problems. But with Diocletian, the right to migrate no longer existed. Thus the reforms of taxation marked two different stages in the descent from civilisation to barbarism, in that they both replaced a money tax by a tax in kind and also replaced the right to migrate by a system that reduced much of the free population to a state of serfdom.

Town and Country

At the same time, the balance was changing between town and countryside. The towns were traditionally the centre of Greek and Roman civilisation. Your citizenship depended on your belonging to a town, and within the towns the leading citizens vied with each other to provide facilities for their town, often in the form of games, sometimes more usefully in the form of architecture, and many of the leading features of classical architecture that we see in the towns were paid for by individual members of the town council.

In the third century, all this changed. The town council was expected to maintain the town and indeed to collect the taxes and the decurions, or magistrates, were responsible for the taxes to which the estates and farms of the district were liable, and thus being a decurion ceased to be a privilege, but became a heavy burden which people sought to avoid.

But if the towns were losing their importance, there were changes too in the countryside. Here the gap between rich and poor widened. One realises how great a leveller is the market place, where one depends for one’s prosperity largely on one’s own ability, and not on the land or position that one has inherited. But in the fourth century, land and its inheritance became all important and land holdings became consolidated into huge estates often with a great villa at their centre; in Roman Britain we have a number of these great fourth century villas which were basically palaces in form.

The crucial question is the position of the tenant farmer, or colonus. In the first and second centuries, tenant farmers flourished, as big landowners found it more profitable to lease out their property to small farmers who paid a rent. Such small farmers were perfectly free to give up their farms at the end of their tenancies, normally for five years, though inevitably most people stayed on the same farm for all their life. But the option to move was always present.

In the 3rd century however, the terms of trade moved against the small farmers, in particular the ever increasing tax demands meant that many of the small farms became unprofitable and the tenants were tempted to give them up and slide away to the cities. Thus many small farms became deserted and the solution was to tie the tenants down and forbid them to move. What happened in practice is that some of the smaller individual farms were abandoned and the cultivators moved into villages.

The same thing was happening in many other trades and professions. In the army in particular recruitment became difficult. In the second century, it was still possible to offer attractive service in the Roman army to Barbarians living beyond the frontier. Many of the troops that served on Hadrian’s Wall had been recruited in Germany and one suspects that in the 2nd century, German was heard frequently on Hadrian’s Wall,  But by the third and fourth centuries, this was no longer possible and it was necessary to lay down that the sons of veterans were obliged to serve in the army too.

Trades were affected too, particularly those concerned with the vital necessity of feeding the population of Rome, that is the shippers and the bakers. The ship owners who owned the ships that brought grain to Rome from Egypt and North Africa had always had a close relationship with the government both in paying extraordinary taxes and having special duties placed on them, and at the same time having extraordinary privileges from the government. Bakers too became a hereditary trade. In many ways the baker is the archetypal capitalist, the touchstone of the existence of the market economy, someone who buys flour from the farmers and then sells it as bread to the end users, and thus a restriction on the bakers signalled in many ways the breakdown of the market economy.

Diocletian was in effect the person who introduced centralised management into the Roman Empire. In the great days, the running of the empire had been amateurish, run on an old boys’ network with a minimum of bureaucracy, few controls and low taxes, and as so often, amateurism worked. Diocletian changed all this. The empire was professionalised: it was divided into four, the taxation system was thoroughly overhauled, a census was taken to find out who was who – and all this cost a lot of money. The numbers of bureaucrats rose enormously – there were soon as many bureaucrats as there were soldiers —and thus taxation had to be raised enormously from the previous low levels in order to pay for all the bureaucracy. It was a vicious circle. The new professionalism certainly gave the empire a new lease of life in the 4th century, but it also carried with it the rigidity and inflexibility that carried the seeds of the decline and fall in the fifth. And most important of all it marked a change from the open society that made the Roman Empire great, to the closed kinship-based society, typical of barbaric societies, the great empires of the pre-market age. There was a loss of freedom: was it worth it?

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