Episode 27: The Empire Strikes Back

Episode 27: The Empire Strikes Back

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We’re back! I hope everyone had a good holiday break. It was a much-needed vacation for me. Before I jump into today’s episode I want to lay out the next few, because there is a lot to cover and I think the best way to do it is to split the episodes thematically. This episode and the next will cover the high politics of Gaul and the revitalized Roman Empire from the rise of Diocletian to the death of Constantine. The following episode will cover this same period while examining the daily lives of the Gauls and those Franks and other Germans who entered Gaul. Then we’ll turn to the rise of Christianity. For a long time Christianity has been in the background of our story, but by the beginning of the 4th century it emerges as one of the most important features of the Roman Empire and, to a lesser extent, Gaul.

Now, some of you may be wondering why I am using the word ‘Gaul’ to describe this land, rather than ‘Gallia’ which was the name of the Roman province for almost three centuries. From here on out I’m going to use the term ‘Gaul’ because within ten years of Diocletian coming to power he divided the Roman world into numerous provinces and dioceses, effectively eliminating the old province of ‘Gallia.’

Alright, enough background, onto the narrative. Where did we leave off last time? Oh yes, the world was on fire. In 274 Roman Emperor Aurelian smashed the breakaway Gallic Empire’s armies and the land of Gaul was back in the Roman Empire…for a year. In 275 Aurelian was assassinated and upstarts and usurpers vied for power in Italy and the East. As bad as this might sound for Rome, Gaul was in an even worse position. Rome had just decimated its local armies and now the claimants to power in the East needed as many soldiers as they could. This left Gaul completely open to invasion by Germanic tribes crossing over the Rhine. Between 276-282 Franks, Vandals and Burgundians sacked 60 towns, including Lutetia, what we now call Paris. These Germans pillaged cities, razed towns and ravaged the countryside, dealing a devastating blow to an already beleaguered country. Many Franks and Burgundians even settled within Gaul, creating their own communities with their own leaders and political structures. For so long the ‘barbarians’ were across Rome’s borders; now they were within Rome and brought with them their languages, way of life and a separate political system.

In 276 Aurelian’s lieutenant Probus seized power and between 280-282 he fought across Gaul. His campaigns were incredibly successful: he defeated all invaders, then went deep into Germania on a punitive expedition. He established forts along the Rhine and prohibited German tribes on the Eastern bank from having large armies. Finally, he took many German hostages in order to ensure their loyalty. But in 282 Probus met the same fate as his old commander when he was assassinated. Through a series of events a Dalmatian military officer named Diocletian had his armies declare him emperor in November 284. But he still had to contend with another claimant to the throne. During this struggle Constantius, the governor of Dalmatia, sided with Diocletian and by 285 he was the clear ruler of the Roman Empire. Diocletian’s reign is generally considered the end of the Crisis of the Third Century as he brought stability and prosperity back to the empire while reforming it so that it could meet its economic and military challenges.

After Diocletian’s armies declared him emperor he made a point not to be ratified in Rome as he did away with even the pretense of Roman senatorial rule, and excluded the senatorial class from his administration. In fact, Diocletian only visited Rome in 304 for his 20-year anniversary when he abdicated *spoiler alert*. Diocletian understood that the Senatorial class and its power base in Rome was a threat to emperors. Senators had incredible wealth and access to important civic and military positions. Meanwhile, the Senate still had ceremonial power, if not actual political power. Diocletian centered the Roman Empire around himself, rather than the Eternal City. He had a travelling court of administrators who relocated with him to whichever part of the empire needed the most attention. Diocletian simultaneously travelled with an army, which meant he was constantly protected from upstarts and assassination attempts. I’ll have more to say about Diocletian’s reforms soon, but just know that Diocletian didn’t set out with a grand vision of how to remake the empire. Changes were ad hoc and often came in response to specific events. Which brings us back to Gaul which was experiencing total socio-political collapse.

By 285 the country of Gaul was in ruins. Franks and Saxons raided along the coast while Germans from numerous tribes ravaged and settled within Gaul. The small towns and countryside were devastated while cities with walls became isolated worlds of Romano-Gallic culture in a sea of lawless violence. Roman officials had extremely limited power and were helpless to defend their territory and keep the economy going. Roving bands of impoverished peasants, shepherds and officially-settled Germans banded together and sacked villas. Eventually these bands of desperate peasants, called Bagaudae, after the Gaulish word for ‘fighter,’ organized into a rebel army and their leaders Aelianus and Amandus claimed to be co-emperors of Gaul. These armies had virtually no structure and no military training, so they haphazardly pillaged the countryside with axes and farm equipment. Meanwhile, what was left of the Rhine legions were stuck on the frontier without steady supply lines.

Diocletian knew something had to be done about Gaul, if not for itself, then to keep the endless hordes of Germans from invading. But at the same time the Goths threatened the Danube frontier and the east was still unstable and threatened by Persia. Diocletian understood that only an emperor could unite the divergent forces of the West and save Gaul. In 285 he declared his trusted subcommander Maximian to the role of Caesar and gave him charge of the West while he ruled the East as Augustus. Diocletian and Maximian had a very special relationship, which some Roman historians have compared to Augustus and Agrippa. Augustus and Diocletian were genius politicians and decent military leaders; Agrippa and Maximian were brilliant generals but lackluster politicians. In both cases, the political leader could manage the empire while their chosen general defeated the enemies of Rome. One major difference though is that while Agrippa had a reputation as a disciplinarian, Maximian could be outrightly cruel, which was perfect for his time. Gaul was in utter collapse and Diocletian couldn’t spare the money to rebuild it. Maximian would have to bring back Roman authority to the West through violence, which was perfect for Diocletian, because it meant his chosen Caesar would do whatever it took to reforge the empire, yet he would be unpopular with the population at large and thus would not threaten his superior.

In 285 Maximian entered Gaul with a large cavalry force which went from town to town, breaking up the Bagaudae. This episode was mostly glossed over in the official Roman histories since it involved brutal crackdowns of Roman citizens. Maximian’s work was inglorious but effective, as he killed off the Bagaudae and Germans alike. By 286 Gaul was largely pacified and the Caesar of the West focused on securing the Rhine frontier. Maximian initially headquartered at Mainz, though Trier became his eventual capital and would remain the capital of Gaul and the northwestern provinces after he left power. From his base at Trier, Maximian launched campaigns along the Rhine to pacify German tribes and reassert Roman authority at the border.

While Maximian was perhaps the greatest general of his time, he was a terrible admiral and had virtually no naval experience. This was problematic because Northern Gaul and Southern Britannia were under constant threat by raiders from Batavia, or what is now the Netherlands. The Saxon and Frankish pirates had swift ships which could evade and outmaneuver Roman ships. In response, Maximian hired a Gaul named Carausius of the Menapii tribe to remake the fleets, establish fortifications in northern Gaul and capture raiding ships. He was so successful in just a year that Diocletian declared victory over Britannia in 286.

What happens next is a point of debate. The official histories record that Carausius was allowing the Franks to raid Britannia and only captured their ships afterward so he could confiscate their booty. Modern historians doubt this occurred, given Carausius had immense support from British merchants. What is more likely is that Maximian distrusted Carausius, who he feared was acquiring too much power and angling to supplant him. Maximian tried to arrest Carausius, but the Gaul escaped and fled with his fleets to Britannia, while Maximian was busy fighting the Germans. Carausius then declared himself Augustus of Imperium Brittanarium, which he modelled on Imperium Galliarum, the former Gallic Empire. Furthermore, Carausius commanded the fortresses and fleets of northern Gaul, so his empire stretched across the Channel.

In  a single moment Maximian’s position suddenly became desperate as he had to fight a war on two fronts. Moreover, Carausius declared himself an Augustus, while Maximian remained a Caesar, which meant that the upstart Gaul outranked the Roman commander. While these were just titles, symbols matter to people, and Maximian feared that many Gauls might oppose the Caesar from Pannonia in favor of an Augustus and fellow Gaul. It didn’t help that Maximian had spent the past year brutally suppressing Gaul and was unpopular with the masses, even if the middle and upper classes supported him.

In April 286 Maximian appealed to Diocletian who agreed that to win the propaganda war, Maximian had to be elevated to Augustus. This was probably not what Diocletian had anticipated; when Diocletian made Maximian Caesar he adopted him as his son, as was the custom. Now that Maximian was an Augustus the two were brothers! Additionally, Diocletian had no male heir and probably wanted to return to the Five Good Emperors’ style of appointing competent rulers, with Maximian possibly being the next in line. But Diocletian was flexible and he adapted to the situation.

Maximian understood he couldn’t challenge Carausius, especially since his only fleet was gone. Yet, Carausius was a long-term problem and couldn’t possibly invade Roman territory for the foreseeable future. Likewise, the coastal Germans were divided, and warred with each other in support of Carausius or Rome. The only immediate threat to Gaul were the Burgundians and Alemanni along the middle and southern Rhine. In 287, Diocletian met with Maximian and they decided Maximian would ravage the Rhine area, creating a zone of death and destruction to scare off the Germans while the elder Augustus invaded from the south. Maximian launched a genocidal rampage along the Eastern bank of the Rhine and through sheer brutality ended the immediate German threat. Far-Western Germania was a graveyard and just beyond the Rhine the German tribes retreated from the punitive campaigns. With the horrified Germans in retreat, Maximian rebuilt the Rhine forts and ordered the construction of a fleet to conquer Britannia.

Maximian then allied with the Frankish king Gennobaudes, who ruled Batavia. Gennobaudes and Maximian’s subcommander Constantius defeated Carausius’ Frankish allies by the Spring of 289, effectively isolating the rebel Gaul. But Carausius remained a thorn in Maximian’s side. The Romans were notoriously bad sailors while Carausius was now an expert at naval engagements. Maximian’s navy met Carausius’ fleet and was crushed. The frustrated Maximian had no idea how he was going to conquer this breakaway empire which threatened Rome existentially and literally. The Britannic Empire didn’t have enough soldiers to outright conquer Roman territory, but it could raid with impunity. Moreover, it was possible Carausius could acquire new allies east of the Rhine, meaning this empire was more than an embarrassment, but a real threat. Carausius was not some incompetent warlord but an effective, well-liked leader who excelled in administration and propaganda. Currency minted in Londinium, Colchester and Boulogne was superior to Rome’s debased currency. By this point Diocletian had instigated a new imperial cult, and equated himself with Jupiter and Maximian with Hercules. When Carausius heard about this he equated himself with Neptune and even minted coins comparing himself to the god of the sea.

By 289, Maximian’s thoughts turned from Britannia and towards his own imperial legacy. He left Gaul and made a palace for himself at Mediolanum, or modern-day Milan, convinced that he couldn’t defeat Carausius. That year he declared that his young son Maxentius would inherit his position as Augustus. Diocletian was furious that Maximian would make a decision without him, since Maximian owed his position to his old commander. Moreover, Diocletian refused to accept the secessionist Britannic Empire. In 292 Diocletian decided that two Augustii weren’t enough to manage the empire. On the first of March 293, in Mediolanum, Maximian grudgingly acquiesced to Diocletian’s demands and elevated Constantius as Caesar of the West, in place of his son. Meanwhile Diocletian elevated Galerius as Caesar in the East. Thus the tetrarchy was born.

The tetrarchy, or ‘rule by four,’ fundamentally changed the nature of the Roman Empire by acknowledging its problems and attempting to correct them. Diocletian recognized that the Roman Empire was too large for two men, let alone one, to rule. The Tetrarchy meant that all regions were under the eye of a Roman emperor, making revolt less likely. Under this scheme, Diocletian ruled Egypt and the Asian provinces while his Caesar Galerius ruled the provinces west of Anatolia and east of Italy. In the West, Maximian ruled Italy, Hispania and Africa, while his Caesar Constantius ruled Gaul and nominally Britannia. These divisions were mostly ad hoc and borders were probably general prerogatives, not set in stone. Furthermore, the Tetrarchy wasn’t very well-defined legally. It was supposed to be a national system wherein each emperor made laws, and had armies and courts. On paper, the Caesars had the same amount of power as the Augustii; likewise the junior Augustus had the same power as the senior. The power arrangement wasn’t meant to be legal, but deferential and cooperative.

Let’s look at the deferential aspect first. All of the emperors had similar legal powers, but the Augustii were far more revered throughout the empire. They had more experience and connections with powerful people. Moreover, Diocletian sponsored a nationwide cult that equated him with Jupiter, the father of the gods and ruler of all existence, and Maximian as Hercules, the greatest soldier who ever lived. For most Romans, to go against the will of Diocletian was to sin against the will of heaven itself. The same goes for disobeying Maximian, to a lesser extent. Finally, the Augustii ruled over wealthier and more populous regions than the Caesars. So while all the emperors were equal on paper, the Augustii, and Diocletian especially, had far more power, resulting in a system of deference from the Caesars to the Augustii and the junior Augustus to the senior.

Now let’s look at the cooperative aspect. Marriage alliances held the tetrarchy together. In the West, Constantius divorced his wife to marry Maximian’s stepdaughter Theodora and in the East Galerius married Diocletian’s daughter Valeria, after which her name became Galeria Valeria; that’s right: Galeria Valeria. I swear I am going to forget half of all the great scientists, emperors and explorers I read about, but I am going to remember Galeria Valeria. Additionally, the Augustii adopted their Caesars into the family and were supposed to abdicate after a ten-year reign at which point the Caesars would become Augustii and new Caesars would be elevated. This system would theoretically offset rebellion since the most powerful and ambitious men would naturally rise to power. Emperors were forced to cooperate since some problems were too large for one man to deal with. As we shall see, when Constantius tried to reconquer Britannia he depended on Maximian holding the Rhine frontier. Finally, because the prerogatives were largely undefined, the emperors had to negotiate solutions to mutual problems and take council with each other.

While deference and cooperation held the Roman world together in theory, in reality, distance was probably the most important factor. The Tetrarchy as a whole never met and these men rarely had to deal with each other. Diocletian wanted to create a unified empire with four leaders, but his system produced four separate powers semi-united through trade, culture, religion and a political system. Each emperor had their own capital. Constantius ruled from Trier, Maximian ruled from Mediolanum, Galerius from Sirmium on the Danube, and Diocletian ruled from Nicomedia. Though in reality, the ‘capital’ was wherever the emperor was.

During this period the office of the emperor changed so much that some Roman historians refer to this as the ‘Dominate’ to distinguish it from the imperial system set up by Augustus called the ‘Principate.’ In the book Romans: From Village to Empire Mary Boatwright et. al note,


“Diocletian’s changes transformed the style of regime established by Augustus as the Principate— with the ruler claiming to be no more than first among equals— into what is now termed the “Dominate,” absolute rule by a remote dominus (master) elevated far above his subjects, and approachable only through innumerable layers of officials and functionaries.”


When we think of Roman emperors we tend to think of them as larger-than-life figures who demanded utmost obedience and worship. Under the Principate this was legally not the case, though in practice megalomaniacs like Caligula, Nero, Commodus and others demanded reverence upon pain of death. Under the Dominate, Diocletian created a system of absolute obedience to the person of the emperor. Diocletian knew Rome could not survive much more internal strife that typified the Crisis of the Third Century and so his system enshrined deference to the emperors who were worshipped as living gods and whose words carried unquestioned legal authority unchecked by the Senate or older traditions. When an emperor visited a city he was greeted with a lavish procession ceremony and all people had to prostrate themselves when entering his presence.

Under the Principate individuals could petition the Emperor who was expected to perform ceremonial functions and work in concert with the Senate. Under the Dominate, emperors were sequestered from their subjects and wielded autocratic power over them. Moreover, the aristocracy under the Principate owed their wealth and power to personal titles. Under the Dominate the aristocracy was a more meritocratic system whose positions were acquired through service to the emperor. Diocletian specifically undermined Italy, Rome, the Senate and the Senatorial class to achieve this. Under the reorganized empire Italy lost its tax-free status and became just another province. Emperors were legitimized by their seniors and were no longer ratified by the Senate or acclaimed by soldiers. Moreover, under the Principate the Empire was divided between Senatorial provinces and Imperial provinces but Diocletian made all provinces subject to imperial administration. Finally, emperors were far less likely to visit Rome. Diocletian only did so for his 20th anniversary, while Constantius never visited it. Finally, the emperors patronized their new capitals and built lavish palaces in them while the Roman palaces were left to decay.

Perhaps Diocletian’s greatest contribution to the empire was the development of an enormous state bureaucracy. During his reign, Diocletian doubled the number of provinces to 101, making them smaller and more manageable. The provinces were roughly split between the militarized frontier, which was concerned with defense, and the inner empire which focused on economic production. Then he created twelve new political units called dioceses, which were groupings of multiple provinces ruled over by a vicar. The old Roman provinces of Gallia, Belgica and the two Germanies were split between Viennensis, which was most of the south, and Gallarium in the north and east.

Diocletian was rightly paranoid about usurpers and split the civil and military administration. This hamstrung any would-be usurper generals since the military depended on civilian administration for its supplies. This also made both services more effective because they were more specialized. The well-educated, law-minded Roman administrators didn’t have to learn about military tactics. Meanwhile soldiers could focus solely on fighting. This meant less-educated career soldiers could advance, which was particularly important since Germans, Goths and other non-Romans increasingly entered into the military. Now that Roman soldiers didn’t have to be educated in law and philosophy, hell, many were even illiterate, wise German tacticians rose up the ranks and became an essential part of the Western military.

Speaking of the military, Diocletian made major reforms to that as well. He understood that the age of pitched battles was largely over. Instead of a large, semi-mobile army, Rome needed smaller, rapid forces to counter raiders. Diocletian decreased the number of men in a legion from roughly 5,000 to 1,000. Then he split the military between the mobile, cavalry-led forces and the infantry who held strategic locations. Furthermore, he did away with much of the old Roman-style all-purpose army tactics. Romans no longer carried all their gear with them, but had gear stationed in fortresses and walled cities. Furthermore, the armies no longer built a fort every night only to burn it in the morning. After all, many cities now had their own walls which troops could hide behind. Under Diocletian, soldiers travelled from defensive location to defensive location. The old, infinitely-hardy Roman soldiers of Julius Caesar’s day were no more, but in their place Diocletian created a segmented, more responsive military apparatus which could repel barbarian invasions while simultaneously incorporating them into the army.

All of these reforms meant there was continual correspondence between administrators. This meant there was more information and the administration was more responsive to economic and military needs. At the same time the expansion of bureaucracy and the military was very expensive at a time when Rome was struggling economically, especially Gaul which was only just recovering from its worst period since Vercingetorix’s war to the death against Caesar over three hundred years prior. Diocletian reevaluated Roman coinage, made a fairer and more practical tax system, and eliminated tax exemptions. New censuses determined tax assessments, and tax rates could even be adjusted yearly, which meant taxation was less arbitrary. Finally, the government accepted payment in kind, which was crucial due to Rome’s still unstable currency.

All of these reforms fundamentally transformed the Roman world. From Augustus to Antoninus the Roman Empire was the world’s largest forum where people, goods and ideas crisscrossed the Mediterranean, which was made possible by a well-guarded series of borders. Now, Rome was in survival mode. Taxes were high, all landowners were conscripted into the army or had to find a replacement. The borders were semi-porous and their function was to allow small groups in while keeping out large waves of migrants that might overwhelm the provinces. Finally the empire was divided between West and East, and further divided between four regional rulers each with their own courts, capitals and administration. The old Rome was gone, as evidenced by the fact that Rome itself was no longer the nation’s capital. Instead, Rome was centerless but adaptive, its indomitable strength exchanged for flexibility.

All of these changes had an enormous impact upon the Roman world, of which Gaul was probably the most effected. The Gallic population and economy was too weak to hold off Germanic invaders by themselves. All of these reforms meant that Franks were continually resettled within Gaul and incorporated into the army as infantry but increasingly as military commanders. And Constantius didn’t just settle allied Franks within his territory; he went so far as to resettle prisoners of war within Gaul, though he scattered them across Gaul so that they didn’t link up with other tribes and cause trouble. Under Constantius Gaul revived and transformed. The mass settlement of Franks replenished the population, especially the military, and brought in more taxable wealth. By the end of Constantius’ reign Gaul was a well-populated territory with a decent economy. But Celtic Gaul was in marked decline as the German tribes began remaking the land in their own fashion.

But I’m getting ahead of myself. Constantius still had a major obstacle to face: the reconquest of northern Gaul and Britannia. Constantius knew that his position as Caesar, his legacy, and the inheritance of his young son Constantine, all depended on defeating the secessionist state. Constantius learned from Maximian’s failures and decided that instead of meeting Carausius in pitched naval battle he first had to reconquer northern Gaul. Constantius marched an army to the walled city at Boulogne and prepared for a siege. He then employed the old Roman tactic of clever engineering. Constantius’ soldiers created a makeshift dam around Boulogne’s harbor and filled it with stones. Trapped and isolated from reinforcements and food supplies, the city surrendered. When the other northern Gallic cities heard about this they quickly pledged their loyalty to Constantius and Rome. Over the next two years Northern Gaul was back under Roman control.

The loss of northern bases in Gaul was a deathblow to the breakaway empire. Without them Britannia had no way of preparing for a naval invasion. Britannia had a fantastic navy but a woefully inferior army, meaning that if the Romans could land an army the war would be over in short order. The British elites were incensed that Carausius had lost northern Gaul and assassinated him in 293, replacing him with his finance minister, Allectus, who became the new emperor. Meanwhile, Constantius spent the next two years on punitive campaigns against Britannia’s Frankish allies all while building up his fleet.

In 295 Constantius was ready to make his move. Constantius knew he just had to land one army in Britannia and the war would be over, so he split his forces. He landed with an army at modern-day Dover while a subcommander landed near the Isle of Wight. Fortune was on the Romans’ side and a thick fog kept the British navy from seeing the Roman ships, which allowed them to land without a fight. This was a nightmare for Allectus, because now he had to face far superior land forces. He assembled the largest army he could and met Constantius’ subcommander. But this finance minister was no general and he and his forces were slaughtered.

What happens next depends on whether or not you trust official Roman histories. According to Constantius, a Frankish army stationed in Britannia that had allied with Allectus saw that Britannia was lost and decided to march on Londinium to sack the wealthy city before fleeing back to Germania loaded with plunder. Constantius raced his army towards the city and slaughtered the Franks just before they could arrive, saving it from the barbarians. Afterwards he took Londinium without a fight and its people hailed him as a hero and liberator. However, it’s possible this is propaganda and that the Franks decided to capture the undefended city, man the walls and try to hold off a siege. We’ll never know for sure, and honestly both are possible. The Franks were long-time allies of Britons and may have wanted to help the breakaway country, but they also had a history of raiding. Either way, Constantius massacred his enemies and the Britons hailed him as their emperor…because what other choice did they have?

By 296 Constantius eliminated all of the rebellious Britons and brought Britannia under Roman rule and his own personal jurisdiction. Constantius had secured his place as a Caesar and future Augustus by stabilizing the West. The Roman world was secure and prospering under the Tetrarchy. But if we look past the propaganda we can see a number of problems developing under the surface. Diocletian envisioned the Tetrarchy as a cooperative arrangement but he was wise enough to know that each emperor’s personal ambitions outweighed their love of a prosperous Rome. As such, the senior Augustus kept Constantius’ son Constantine with him as an unofficial hostage to ensure Constantius’ loyalty. This wasn’t an immediate problem since Diocletian treated Constantine with respect, made him a prominent member of high society and taught him the ways of war. But the eastern Caesar Galerius viewed Constantius’ as a threat to his power and it became clear to everyone that as soon as Galerius replaced Diocletian Constantine’s life would be in danger.

The other major point of tension in the empire was over religious divisions. From Rome’s founding through the reign of Marcus Aurelius the overwhelming majority of Roman citizens practiced Roman polytheism. From our modern perspective Roman polytheism wasn’t a unified religion, as people across the empire worshipped numerous different gods and had wildly different beliefs. Yet, there were common religious rites, practices a national priesthood with the pontifex maximus as its head. Furthermore, Roman polytheism was tied to the worship of the city of Rome, the patron deities of Rome and of the emperors themselves. In Rome one might worship Jupiter while in Thebes one might worship Ra, but both were equated with the Roman emperors and their priests were part of a Roman state system that furthered the interests of the empire.

Before the third century, mystery religions and cults represented the largest religious minorities. These had always been a part of the Roman Empire and expansion into the east brought Zoroastrianism, and the cult of Mithras into Roman territory along with the relatively small religion of Judaism. But these religions were relatively small. During the Crisis of the Third Century Roman temples were neglected, the priesthood was in chaos, festivals went unfunded and the spiritual needs of the Roman people were ignored or maligned by the Roman state. Since Roman religion was tied to the state the forty-nine years of continual bloodshed, plague, economic decline and chaos made many turn away from traditional beliefs.

During this period two small religions in the Eastern Roman Empire skyrocketed in popularity: Manichaeism and Christianity. I’m not going to dwell much on Manichaeism because it didn’t have much presence at all in Gaul or the West, but it’s worth briefly mentioning. Manichaeism was a religion founded in Persia in the 3rd century CE and shared many similarities with Christianity as it postulated a dualistic universe of good versus evil. Manichaeism died out due to persecutions in the Eastern Roman Empire, Persia and later the Islamic kingdoms, but that’s a different story. For our story what’s important is that Manichaeism and Christianity were rapidly supplanting Roman polytheism. Around 300 CE roughly 10% of the Roman Empire as a whole was Christian, but in some Eastern provinces this could have been as high as 1/3rd. Combined with Manicheans, monotheists outnumbered polytheists in numerous Roman territories.

The rapid rise of these two monotheistic religions disturbed Diocletian. He had spent the better part of his reign promoting traditional Roman beliefs, rebuilding temples, patronizing festivals and remaking the priesthood. The old Augustus was notably using Roman polytheism to unite the empire and extol the glory of Rome, himself and the Tetrarchic system but by all accounts he was a devout believer in the old gods. He believed that these new monotheists, who refused to engage in ritual sacrifice, offended the gods, which in turn threatened Rome’s security. Moreover, these monotheists didn’t acknowledge the emperors as living gods, which undermined their authority. Diocletian disliked monotheists and particularly Christians due to their large population. But he was worried that persecutions would do more harm than good. Meanwhile his Caesar Galerius consistently told Diocletian that something needed to be done about the Christians and he was more than willing to spill some blood to restore the old ways.

In 299 Diocletian began his first purges when he removed Christians from the civil service and the army. The initial persecutions only emboldened the Christians who willingly accepted martyrdom for their beliefs. On the 24th of February 303 Diocletian began what is known to history as ‘The Great Persecution’ when he issued the first of four edicts against Christians. This edict declared that churches would be demolished, Bibles publicly burnt, assemblies prohibited and unrepentent Christians removed from office and lose civil rights. This was followed by a second edict which arrested bishops and priests and a third edict which allowed clemency for those who offered sacrifices. A fourth and final edict demanded that all people engage in public sacrifice and those who refused would be executed.

These edicts caused a great deal of violence and turmoil in the East. But in the West the edicts were largely ignored. Maximian only enforced the first edict, which meant Christians in Italy, Hispania and North Africa were pushed out of public life but otherwise left alone. Meanwhile Constantius barely even followed the first edict. He ordered a few churches burned and removed Christians from his own court but otherwise left Christians alone. Constantius probably didn’t have any particular affection for Christians; there’s no evidence he ever converted, despite Constantine’s later propaganda. For Constantius, Christians weren’t a problem because there really weren’t many in the West. Perhaps 5% of the population of Gaul were Christian. There were some Christians in high-ranking positions and the major cities had temples but otherwise they were a small, quiet minority. The Western Caesar thought that persecuting these people would cause more harm than good, especially in Gaul which was still recovering from its near-total collapse less than twenty years prior. Moreover, he didn’t want to persecute Christians because the Christians were all Roman citizens. If he killed off Romans at a time when Germans were coming into his country Gaul’s Roman culture and civic structure would be even more threatened by these migrating non-Romans. Constantius decided to live and let live, and only pretended to oppose Christians in order to appease Diocletian. This move would have an enormous effect on later developments because peace and prosperity in the West meant it could rebuild while the rich and populous East weakened itself.

The years 303-4 marked the 20th anniversary of Diocletian’s reign and the tenth anniversary of the Caesars. Diocletian decided to commemorate this occasion with an elaborate ceremony, wherein he finally visited the Eternal City. While there Diocletian fell deathly ill in the winter of 304-305 and many Romans believed he had passed on. By early 305 the old Augustus recovered from his illness but he was exhausted, weak and a shell of the man he had been. With his final act as emperor he declared that he and Maximian would retire, give up their position as Augustii to their Caesars, and elevate two new Caesars to take their place.

Diocletian had an incredible career, and was hailed as the savior of Rome. He had brought it from the brink of collapse and created a political, administrative, military and economic system that addressed the challenges of his time. Now the old man wanted to retire to a villa and watch his beloved country prosper. But his final decision as emperor proved utterly disastrous and set Rome up for future conflict. Most Romans had expected Constantius’ and Maximian’s sons to be the new Caesars. Virtually everyone was shocked when Diocletian chose two of Galerius’ hand-picked supporters as the new emperors. Valerius Severus became the Caesar of the West, ruling Italy and Africa while Valerius Daia became Caesar of the East, ruling Egypt, Syria and eastern Anatolia while Galerius added Western Anatolia to his domains. In an instant, Augustus Galerius, a man who had a reputation for brutality against his own people during the persecution of Christians, and as a conniver who had taken advantage of the sick, old Diocletian, had made his cronies emperors.

I can only imagine the whirlwind of emotions that Constantius must have felt when each piece of news came to him. He must have felt elated when he heard he would become the new Augustus of the West and add Hispania to his territories. Then he must have been struck dumb to hear that his cruel rival suddenly had near-total power over the empire. I imagine that dread overtook him when he realized that his son Constantine was still in the East and under the power of a living god who wanted him dead. But Constantine’s story doesn’t end with a knife in the dark, and next time this young man will march to Gaul and his destiny.



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Ed. David S. Potter, A Companion to the Roman Empire, 2006.

Elton, Hugh, The Roman Empire in Late Antiquity: A Political and Military History, 2018.

Drinkwater, J.E., Roman Gaul, 1983

Gregory of Tours’ The History of the Franks

Heather, Peter, The Fall of the Roman Empire: A New History of Rome and the Barbarians, 2005.

Herodian’s History of the Empire from the Death of Marcus

Mary T. Boatwright, Daniel J. Gargola, and Richard J. A. Talbert, Romans: From Village to Empire, 2004.

Mitchell, Stephen, A History of the Later Roman Empire, AD 284-641: The Transformation of the Ancient World, 2007.

Sessa, Kristina, Daily Life in Late Antiquity, 2018

Williams, Stephen, Diocletian and the Roman Recovery, 1985.

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