Diocletian transforms the Roman world through rational and autocratic reforms, discarding the system Augustus had built nearly three centuries earlier and forging an entirely new order.

Below, you can see Diocletian’s reformed empire in the year 300 CE. The Mediterranean world was divided into four regions, each ruled by an emperor with a capital near the border.

Diocletian oversaw the eastern part, which combined Anatolia, Syria, Palestine, and Egypt. His heir, Galerius, governed the Danubian district, which united Pannonia, Moesia, and Thrace.
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Maximian ran the Mediterranean sector, which combined Hispania, Africa, and Italia. His heir, Constantius, administered the western region, which united Britannia, Gaul, and Germania.

​The map below zooms in on the Lower Danube, a region which was ruled by Galerius. You can see the borders of the original province of Dacia, as well as its roads and cities.

The new, smaller province of Dacia established by Aurelian lies south of the Danube; it included three cities north of the river which had remained under Roman control, and it’s through these cities that the empire continued to trade with the people beyond the Danube.

You can also see the provinces created by Diocletian in the region. Most pertinent to our story is that Moesia Superior and Moesia Inferior no longer exist; Aurelian took territory from the two of them to create his new Dacia, and Diocletian renamed them Moesia I and Moesia II. Part of Moesia II was taken to create Scythia, a province named after the ancient nomadic peoples we’ve seen at the beginning of our story.

Transcript

Hello and welcome to A history of Romania.

Season 1, Episode 17: Reforging

The last episode saw the end of the crisis that had rocked the Roman world in the middle of the 3^rd century. Aurelian had put the empire’s broken pieces back together, with the notable exception of Dacia. Tribes of Iazyges, Carpi, and Goths had migrated on the territory of the former province, and its inhabitants had to find a balance with their new neighbours. We ended with the ascension of emperor Diocletian in 285, and we’ll spend this episode looking at his reign, because the changes he would bring to the Roman world would have profound consequences for people on both sides of the frontiers.

The Roman empire had had twenty-seven emperors during the last 50 years of instability, which is more than in the previous 262 years since Augustus came to power. This period of crisis saw one general after another claim the throne at the first opportunity, and each contender thought he would be the one to break the cycle, secure his hold on power, stabilize the empire, and pass the throne to his son. And all twenty-seven men had been wrong.

Our twenty-eighth man, Diocletian, had been born in the 240s and had lived through the worst of the crisis; he was well aware of the pattern and sought to do things differently. After he defeated all other contenders to the throne in 285, he looked to secure his reign by naming an heir. Usually, a ruling emperor, called by the title Augustus, would name his son as his successor, and give him the title of Caesar. But Diocletian wasn’t looking to start a new dynasty; he was looking to completely change the system, so he instead chose a man outside of his family to be Caesar: it was his most trusted officer, Maximian.

At this point, barbarian invasions and rebel uprisings were still ongoing, so Diocletian told Maximian to oversee the western part of the empire while he himself took the eastern part. To give his colleague further legitimacy, he elevated Maximian to the office of Augustus in 286, making him his equal. This decision showed the immense trust that existed between the two men, and it was yet another departure from custom: the last co-emperors not related by blood had been Marcus Aurelius and Lucius Verus, more than 120 years ago.

And this trust paid off. Diocletian and Maximian spent the next half dozen years putting down rebellions, repelling raids, and conducting wars in their two halves of the empire. By the early 290s, the situation was stable enough for Diocletian to begin reforms that he had been thinking about for the past decade.

In 293, Diocletian doubled the number of emperors from two to four, which completely changed the character of the empire. The Romans had benefitted from having a ruler in the West and one in the East, but in his mind, that wasn’t enough; for the administration to be as efficient and as flexible as possible, the empire needed to be divided into even smaller zones that would enjoy the full attention of a ruler who could focus on local projects, respond to threats quickly, and who had the authority of an emperor to deal with usurpers and foreign leaders.

Accordingly, Diocletian divided the Roman world into four regions, and there’s a map in the description to help you visualize what I’m about to explain. A western part combined Britannia, Gaul, and Germania; a Mediterranean part united Hispania, Africa, and Italia; a Danubian part combined Pannonia, Moesia, and Thrace; and an eastern part united Anatolia, Syria, Palestine, and Egypt.

Each of these four regions had its own capital: there was Trier near the Rhine, Milan near the Alps, Sirmium on the Danube, and Nicomedia near the Bosphorus. You may have noticed that none of these include Rome, and that was a conscious choice: the cities that became capitals were chosen because they were close to the frontiers, which would allow the emperors to deal swiftly with invaders.

But not all regions held the same importance. The eastern district had the richest provinces and the most threatening foe – the Persians – so it was led by Diocletian. The Mediterranean district included the spiritual heartland of the empire, so it was overseen by Maximian. That left the western region and the Danubian region, which would be taken by the two new emperors. These men would not have the same authority as Diocletian and Maximian; they would be Caesars, the heirs to the two Augusti.

To fill these critical positions, the ruling emperors chose two distinguished generals as their heirs and then married them to their daughters to strengthen the ties between them. A man named Galerius married Diocletian’s daughter and was put in charge of the Danubian region, while Constantius married Maximian’s daughter and was given the western district.

Each man would lead his own army from his capital near the frontier, which made the government more responsive to threats and also removed the prospect of a successful general gaining glory and claiming the throne. More than that, there was no possibility for a rebel to dispute the succession, since continuity of rule was assured: the Caesars were known to be the heirs of the Augusti, and they gained legitimacy daily by actively administering a part of the empire.

In effect, the state now had two junior emperors and two senior emperors, with Diocletian being the unofficial leader who set the agenda. But officially, the government made great efforts to emphasise the unity of the four men. The state wanted to avoid any allusions to the period of disorder that had characterized the last fifty years. The four emperors were presented as equals, and several inscriptions actually show them with identical features. Their districts weren’t formally delimitated either; they were treated more as spheres of influence. Galerius, for instance, fought revolts in Egypt and campaigns against the Persians before returning to his Danubian district. The imperial propaganda conveyed the message that the empire was administered by four brotherly emperors who came to each other’s aid in times of need, and who, in calmer times, devoted their full attention to a portion of the state.

Doubling the number of emperors was only the first of Diocletian’s reforms. The leading emperor also doubled the number of provinces, not by adding new territory, but by reducing the size of each province. The reason behind this change was that governors had small staffs that weren’t as efficient as Diocletian wanted them to be. By reducing the size of their jurisdiction, he ensured governors could better focus their efforts and more effectively collect taxes, administer justice, and maintain infrastructure.

However, doubling the number of provinces threatened to overwhelm the emperors with daily reports and requests, so Diocletian added a few layers between the top and bottom of the administration. The ninety-six provinces of the empire were grouped into twelve dioceses, each led by a vicarius, meaning “deputy.” These vicarii would not report an emperor directly, but to a Praetorian Prefect, so that only the most important matters made it to the imperial desk.

Now we’ve encountered Praetorian Prefects a lot throughout our story; they were the commanders of the Praetorian Guard which was meant to defend the emperor, but which had often gained so much influence as to murder their ruler and put their own candidate in power. Well, Diocletian stripped away their influence by making them the garrison of the city of Rome, but he kept their commander near his side and made him his top bureaucrat. As such, each emperor would have a Praetorian Prefect that would manage the administrative staff and help him with daily operations.

Diocletian’s new system was a rational but complicated one. To put it in a single sentence, there were ninety-six governors, who were directed by twelve vicarii, who reported to four Praetorian Prefects, who each worked for one of the four emperors.

That was only the civilian side of the government; we also have to talk about the military. Diocletian fully separated the civilian from the military by taking away the power of governors to command armies. He did this for two reasons: one, it would remove their ability to revolt, and two, it allowed them to focus on civilian administration. In turn, he created the role of dux, meaning “leader,” whose only job was to lead troops. As such, each role could fully concentrate on their own area of expertise, which would make both of them better at their jobs.

The new role of dux was part of a larger reform of the military. Diocletian separated the Roman army into two: the mobile comitatenses and the static limitanei. The crisis years had muddled the whole system of legions; as invasions multiplied, legions in quieter regions of the front sent part of their forces to help out their brethren in more dangerous areas. These small cohorts sometimes returned to their original legion, but most times, they remained in place and became the official unit guarding that area of the front.

Diocletian now took these small cohorts and turned them into the standard unit of the Roman army: the comitatenses, which is derived from the Latin word for “company.” These contingents contained about a thousand soldiers – much less than the six thousand that had composed the legions – and so were more flexible while still being able to come together into larger units if a sizeable threat materialized. The comitatenses were under the command of the emperor, and he marched them wherever he needed to go, whether it was to fight a usurper or defeat a tribe beyond the frontiers.

While the emperor campaigned, there needed to be a force that stayed behind to defend the border. As you know, a huge problem during the crisis had been that, when a general saw a chance to gain the throne, he headed for Rome and left the front undefended. So, Diocletian formed the limitanei, meaning “soldiers in frontier districts.” These units were recruited from the local population along the border and garrisoned urban defenses, forts, bridgeheads, and watchtowers. They were led by a dux, and their mission was to patrol the border and defeat bandits, but if an invading force approached, they were to inform the emperor and hold their fortifications. They would then slow down the enemy until the emperor arrived with the main force.

To fill the ranks of the limitanei and comitatenses and ensure no enemy would ever again roam inside the empire, Diocletian massively expanded the army from around 350,000 to 500,000 soldiers. This increase mainly went to the frontier troops, who were paid less, and there were about twice as many limitanei as comitatenses.

Of course, the expansion of the administration and of the army meant that the state had to pay many more salaries, which pushed Diocletian to reform the tax system. During the crisis years, successive emperors had devalued coins and minted more and more of them to meet their needs, which led to every coin being worth less; inflation surged to such an extent that many people switched to bartering goods and services. The army had been forced to adapt too. Since coins had lost so much value, the military just took goods from the local population as tax, and used those to directly supply units and pay soldiers.

Coins were of course still used, and ideally, Diocletian would’ve wanted to use coins for everything; but he realized that until inflation was brought under control, this system of taxation based on goods and services was extremely useful to keep things running. But it was messy, and he wanted to rationalize it. So, the emperors sent out agents to every settlement in their realms to take a census of all the inhabitants, their professions, their goods, animals, lands, and anything else of value. With this information, the emperors then set a tax rate for every settlement based on what they could provide: some communities gave bushels of wheat, others flocks of chickens, and others repaired the army’s weapons or transported their tents. The improvised system of requisitioning was thus organized and centralized, and tax revenue increased significantly.

But now that taxation was based on what each settlement could give in terms of goods and services, it was imperative that people stayed in the same jobs; because if all the farmers in a village decided to become potters, then the state would receive pots instead of wheat, and it couldn’t feed its soldiers with empty pots. To prevent people from changing jobs, the state used the information in the census to group workers into guilds that were supervised by the government. Not only could you not leave the guild, you couldn’t even move to another settlement without permission, and you had to pass on your profession to your children to ensure that they would continue to provide the state with what it needed. So if you were a farmer, your children would be farmers, and if you were a potter, your children would be potters. And the place where you were born was the place where you were going to die, and it would be the same for your children.

Diocletian’s reforms didn’t aim to bring the empire back to what it had been before the crisis; they aimed to reforge it into a state adapted to a new reality. For him, that meant the emperors would have total control over society through an administration that was rational and unchangeable.

The emperors didn’t sit still while these reforms were being implemented in the 290s. Diocletian used his mobile comitatenses to campaign north of the Danube in 294 against the Iazyges, and in 296 against the Carpi. Galerius then took the lead in 299 and 302, gaining the title of Carpicus Maximus six times. These attacks were launched from the Dacian cities that the Romans had kept as bridgeheads north of the Danube. The emperors expanded their walls, erected forts, and built roads to connect them, further reinforcing their position. The Romans didn’t wait to be attacked, but adopted a strategy of active defense by striking the barbarians to weaken them before they could threaten the empire.

While north of the Danube, Diocletian and Galerius captured thousands of Carpi civilians and brought them south of the river, as Aurelian had done. It’s possible that they could’ve also taken Romans that had remained in the area but which now wanted to return to the empire. We have no literary or archeological evidence of this, but I wanted to mention it as a possibility, because the Danubian frontier was not a static, impenetrable border; people on both sides of the river continued to have close contacts with each other, and unofficial movement was possible.

Indeed, archeologists have found numerous Roman coins north of the Danube that were minted after the evacuation of Dacia, which tells us an interesting story. A few of these coins are made of gold, and they probably found their way there as tribute: as we’ve seen in the past, when the empire courted barbarian leaders, it gave them luxury goods as gifts alongside money, which was often in gold form. But the vast majority of coins found by archeologists are made of bronze or silver, which weren’t used for tribute, but for commercial transactions. The migratory peoples who had moved on the territory of the former province weren’t used to dealing with coinage; they had always conducted their business through barter, and they continued to do so now. The only communities which used coinage as a regular means of exchange would’ve been the Romans who had stayed behind, and this is corroborated by the fact these coins were found in cities, existing rural settlements, and former castra – all areas inhabited by Romans, not migratory peoples. Since many of these coins were minted after the evacuation, the implication is that these former imperial subjects continued to trade with the empire after the loss of Dacia. And this makes sense.

By the 290s, the first Romans who had been born inside the empire but who had lived most of their lives outside of it north of the Danube were coming of age. As adults, they became the main workforce in their communities, and their parents could’ve easily shown them the roads they had travelled when Dacia was still part of the empire. Indeed, the imperial roads were still there – the evacuation hadn’t destroyed them. So the Romans around the Carpathians could’ve travelled to the cities on the north bank of the Danube, sold their grain, cheese, wool, and salt, and returned home with bronze coins and goods manufactured in the empire. The extent of these trade networks must’ve been vast, as we’ve found coins in the city of Napoca, in the far north of the former province. I’ve included a second map in this episode’s description that focuses on the Lower Danube. You’ll be able to see the imperial roads in the former province of Dacia, as well as the new Balkan provinces created by Diocletian.

Of course, we might wonder why the Gothic or Dacian leaders of the area would let their Roman neighbours travel to the empire, and we don’t have a definite answer. My guess is that the migratory peoples realized the cities of the empire were much more likely to open their gates to their former compatriots than to barbarians. There was a natural affinity between the Romans to the north of the Danube and those to the south, as they both spoke the same language and had the same cultural reference points. It had only been about twenty years since the evacuation, and the refugees who had left would’ve now been frozen in place by Diocletian’s policies, forced to remain where they had first been settled and forced to continue in the jobs they had always had. As such, there were many people just south of the Danube that were former inhabitants of Dacia, and who were intimately acquainted with its Roman communities; they would’ve known what towns were renowned for what goods, and could even have known some of the people who came south to trade. And so, Dacian and Gothic communities benefitted from trade between their Roman neighbours and the empire, because these neighbours brought back goods that they would otherwise not have access to. Allowing this sort of trade was in everyone’s interest.

By the end of the 3^rd century, Diocletian’s reformed Roman empire was running smoothly. The administration was more efficient than ever, the army kept the borders safe, the economy had begun to recover, and the population faithfully followed their four emperors. Well, that last part is not actually true, because there was a segment of the population that didn’t faithfully follow their four emperors; these subversives were the followers of Jesus of Nazareth.

We’ve encountered this group before in episode eleven, but they deserve a fuller introduction. The story begins with Jesus, who was a Jewish preacher from the province of Judea with a unique interpretation of Judaism. The Jewish people believed there was only one God, as opposed to the Romans who believed in many. This God had created the world and chosen them to be a holy nation; they had to adhere to his laws, and in turn he would give them land and blessings. At some point, a messiah would emerge among the Jewish people, and he would bring about a golden age.

Jesus claimed that he was that messiah sent by God. Among many other things, he taught that you should love your neighbour and your enemy, forgive those who have wronged you, help the sick and poor, and repent for your sins, and that if you did so, you would enjoy eternal life. A portion of the Jewish community believed him, but another didn’t and actively opposed him. The Roman state wasn’t fond of him either; it saw Jesus as a threat to the social order and, in the year 33, crucified him. Yet his followers reported that, three days later, he returned from the dead and then continued to preach for forty days before ascending to Heaven.

These followers believed he would soon return and establish the kingdom of God on Earth, and they continued to spread his teachings. After some debate, they decided that you didn’t have to be Jewish to be part of their community, which led to an influx of converts from sympathetic Romans. By the end of the 1^st century, the followers of Jesus were seen as clearly distinct from the Jews, and they came to be called Christians, because Jesus was christos, which is the Greek word for “messiah.” In fact, that’s how you say Jesus Christ in Romanian today: Isus Hristos.

Over the next two centuries, the Christians spread from Judea all across the Roman world and developed communities with a hierarchy of their own. Deacons helped the sick and poor; presbyters oversaw the affairs of the Christian community; and bishops interpreted scripture and acted as leaders.

The empire had always had a plurality of religions, but these Christians posed a problem, because they didn’t believe in the Roman pantheon, didn’t offer sacrifices to the imperial family, and were organised in a structure that was outside of the state’s control. Some emperors had persecuted them since they were an easy target to blame when things went wrong; emperors could say: “Look, I know things are bad, but it’s not my fault; the real problem is these people in this weird cult working in the shadows; who knows what they’re up to?” And while a couple of emperors had used that trick, most hadn’t had time to focus on the Christians; they had much bigger problems to deal with.

But by now the Christians had grown in number, and Diocletian was paying attention. His reforms touched every aspect of life, including religion. In fact, religion was intimately tied to the legitimacy of the emperors. You see, Diocletian had been elevated by the army, but he didn’t want that to ever happen again; he wanted to take away the power of the army and even that of the Senate to appoint emperors so as to make it impossible to change the current system. As such, he decided to rest his legitimacy on something no possible adversary could control: the divine.

When he came to power, Diocletian assumed the title of Jupiter, the supreme god of the Roman pantheon, and gave Maximian the title of Hercules, his son. The message was clear: the Augusti were the representatives of the gods on Earth. They couldn’t be dislodged through army coups or the decisions of senators because their authority didn’t come from the soldiers or the people of Rome; it came from the gods.

To cement this idea, Diocletian enacted protocols that put the emperors above everyone else. He began wearing a crown and ordered that people had to prostrate themselves before him. The emperor was no longer the first among equals, as Augustus had claimed; he was a divinely ordained ruler above his subjects.

The problem was that the Christians didn’t recognize the Roman pantheon and didn’t believe that their God had appointed Diocletian and Maximian as their rulers, which was a direct threat to their legitimacy. And though Christians made up only about ten percent of the population in the year 300, they had converts from every social class, from enslaved workers to farmers, artisans, soldiers, landholders, and even some members of Diocletian’s court. In the emperor’s view, these traitors had infiltrated every part of society.

He had worked tirelessly for the past fifteen years to construct an empire that could thrive in the new world the Romans found themselves in after the crisis. The easy part had been to tell people what to do; the hard part was making them think it was the right thing to do. If he wanted his changes to be permanent, he had to make people believe in the system and make them loyal and willing subjects. If he didn’t do that, all his regions and roles and rules would not be followed, and all his efforts would come to nothing.

In Diocletian’s mind, the Christians were a group of dissidents whose beliefs brought into question his very authority, and whose activities relied on a secretive hierarchy outside of his control. If he wanted his reformation of the Roman empire to last, he needed to root out their religion. And next time, we’ll see him attempt to do just that.