113 - Three Empires

Hello, and welcome to the History of Rome, episode 113, Three Empires. Though I haven't yet stated it explicitly, I think the nature of the military campaigns the Romans have lately been engaged in against the Goths and the Sassanids and the Franks and the Alamanni collectively speak for themselves. The Romans are now on the defensive. For its entire history, Rome had always projected outward. When battles were fought, they were fought in enemy territory. When battles were won, they enriched the empire with new wealth and new subjects. When battles were lost, it simply slowed the rate of Roman expansion. But now, the battles are being fought in Roman territory. When these battles are won, the reward is little more than a temporary peace, and far from enriching the empire, even victory was now a net loss on the balance sheet, in men, in money, in economic impact. And when those battles are lost, well, the very foundation of imperial legitimacy was the ability to provide physical security for its citizens, so you do the math.

In 260 AD, this legitimacy was finally shattered by simultaneous attacks on all the major frontiers. When the central government proved itself unable to provide the security demanded by its people, the people abandoned the central government, and the Roman Empire broke apart. Now one thing that we should clear up right off the bat is that while the administrative reach of Gallienus' government is about to be radically reduced, at no point should the rise of the Gallic and Palmyrene Empires be viewed as a repudiation of Roman values. Posthumous' Gallic Empire may have seceded from the Union as it were, but it did not reject the values, forms, or ideals that that Union had been based upon. Right down to its Senate, annually elected consuls, and praetorian guard, the Gallic Empire was in every sense a Roman Empire, pursuing Roman policies in a Roman fashion.

In the East, the career of Odinothus was at all times acknowledged as occurring within the established structure of the Empire. He was, for all intents and purposes, leading an independent kingdom, but both he and Gallienus recognized the expediency of allowing Rome to officially bless the new leader of the East, to cloak Odinothus' actions behind a screen of imperial titles and offices to make it seem as if the two men were partners rather than rivals. Odinothus never pressed for the title of Augustus, and Gallienus never attempted to assert control over the East, and this was a state of affairs that suited both just fine for the time being. That is all to say that the 260s did not represent the rise of native independence movements. The decade represented instead an estrangement between the governing elites of the three regions, all of whom bought into the basic Roman political ideologies that had dominated the Mediterranean for the last few centuries.

As I noted in the introduction, the underlying legitimacy crisis that faced the Empire in the 260s was that the central government was no longer able to provide the kind of basic security its citizens had grown to expect. The myriad foreign invaders successfully overrunning the borders and sacking the provinces were not just running off with the Empire's wealth, they were running off with the Empire's raison d'etre. Whether or not there was a set of policies Gallienus could have pursued to create a more unified centrally guided response to the invasions is interesting to think about, but ultimately irrelevant. He did not do so, and was very likely unable to do so. And it's not like he was fiddling while Rome burned, he was beating off an invasion of Italy itself when the political structure of the Empire began to fracture. He was doing everything he could, but there was too much to do.

To take the West first, you'll recall that when Gallienus headed to the Danube to put down the revolt of Ingenus, that he elevated his teenage son Salonius to the rank of Caesar, and left the defense of the western provinces in the hands of the eminently capable general Marcus Posthumus. Posthumus shared overall administrative authority with one of the Praetorian prefects who Gallienus had also left behind, a man by the name of Sylvanus. Posthumus and Sylvanus divvied up responsibility for the region between them, with Sylvanus running civilian affairs and looking after young Salonius, while Posthumus controlled the army. And what an army it was. The ranks of the Rhine legions had already been thinned by the recent Frankish invasions, and Gallienus had now absconded with the cream of what was left to go off and fight Ingenus. This put Posthumus in a very tight spot, and put the troops remaining in Gaul on edge. How were they supposed to defend the entire frontier when they were this undermanned and this undersupplied?

Into this atmosphere of fear and resentment stepped a fairly innocuous incident that would lead directly to the secession of the West. A raiding party of Germans was headed back towards the Rhine sometime in mid to late 260, when they were caught and defeated by Posthumus. Well aware that he and the army he had been left with had been assigned a nearly impossible mission, Posthumus decided to take the opportunity to reward his men, and ordered that the captured wealth of the Germans be distributed amongst them. This endeared Posthumus to his soldiers, but it did not endear him to the men who the wealth had been stolen from originally. When Sylvanus heard about all this, he ordered Posthumus to send the property he had recovered back from whence it had come. But Posthumus refused the order. After all, didn't his men deserve something for risking their lives in defense of the provinces? When Sylvanus refused to back down, Posthumus and his army took the next logical step—logical in the context of the third century, anyway—and Posthumus was acclaimed emperor.

He then wheeled around and marched on Cologne, where he planned to force Sylvanus and Salonius to submit to his authority. The young emperor and his guardian attempted to resist, but the far superior resources of Posthumus allowed him to overcome the city defenses and capture his rivals. Well aware that there was no turning back now, Posthumus likely executed Sylvanus and Salonius, and announced that he was taking over control of the Rhine. His agents spread the word, and in no time replies came back from the governors of all three Spanish provinces, all three Gallic provinces, and the island of Britannia, supporting Posthumus' claim to power. Their willingness to support Posthumus was premised on his ability to halt the Germanic invasions that Emperor Gallienus had deemed not important enough to attend to personally. It was not that they did not appreciate Gallienus' presence when he was around, it was just that there was no counting on him to stick around. Twice already he had surveyed the empire and deemed the problems of the west not as important as the problems along the Danube or in Italy. And it is not even that they were arguing that the emperor could or should have done something different, it was just that, well, they couldn't go anywhere. Their homes and families and estates and clients were all stuck here. Whether or not the Frankish invasions were the worst problems the Romans faced was immaterial. When your house is on fire, you want someone to put it out. You don't want someone to tell you that some other, more important building is on fire and that they need to go put out that one first. Posthumus was promising to never leave and to focus on putting out the fire along the Rhine, and so they supported him.

This mandate, though, meant that unlike previous usurping generals, Posthumus could not immediately pack up the army and march to Italy on a mission to overthrow Gallienus. Part of the reason why he was able to rule for a decade over half the empire, which puts his tenure in office amongst the longest of the whole century, by the way, was because he never forgot that his primary responsibility was to protect the west from invasion. By focusing on that limited objective, he was able to rule practically unopposed for ten years. Right away, he reorganized the political order of the west, and invited men of senatorial rank from the provinces loyal to him to meet in Gaul and form a new senate, who would, like their new emperor, focus solely on the administration and safety of the west. No Gothic invasions would distract them, no Sassanid power plays would draw them away. It was time for the west to look out for itself.

Gallienus, of course, was apoplectic. He had spent the majority of his years in office dealing with invasions along the Rhine, and had only abandoned the western frontier when a revolt had broken out along the Danube and when Germans had invaded the home province. What did they want from him? The empire was a big place, and to get all cranky because he couldn't provide them with his undivided attention a hundred percent of the time was, in a word, childish. But as he sat in Milan mopping up after the Alemannic invasion, he quickly realized that as much as it burned him up, there was probably very little he could do right at that moment about Posthumus. There was no doubt that as soon as he was able to, Gallienus was going to revenge himself upon Posthumus, but right now, all those things that had drawn his attention away from the Rhine in the first place were still going on and still getting worse. When Gallienus looked at the big picture, the problems in the west were minor compared to the full-blown emergency that was currently marching across the eastern empire.

Sharpor had taken his capture of Valerian as an invitation to sack as much of the Roman empire as he could get his hands on, possibly with the idea of softening the region up for eventual annexation by the Sassanids. According to some sources, the defeated Edessa had cost the Romans something like seventy thousand men, and though a great deal of those had been brought west by Valerian, the eastern legions were still a pale shadow of their former selves. And they had very little hope of reinforcement, as what imperial forces were available had been mustered by Gallienus to defend Italy. But all was not lost. As the Sassanids crashed into Syria, two Roman officials stepped forward to organize a defense. The first was a general named Ballista, or possibly Callistus, depending on what source you read, who took over the remnants of the legions, and organized a pseudo-guerrilla campaign to harass Sharpor's supply lines, pick off isolated detachments, and generally make life frustrating for the invading Sassanids. The other official was one of Valerian's chief financial officers, a man named Fulvius Macrianus, who had been left behind in Antioch, along with the traveling imperial treasury, when Valerian had marched forward to Edessa. With Ballista's help, Macrianus was able to keep the treasury out of Sharpor's hands, and use it to fund the effort to expel the Sassanids from Roman territory.

For the rest of the year, the two men did everything they could to halt Sharpor, and though they slowed him down, they were unable to prevent him from marching into Asia Minor on a campaign that Sharpor's own propaganda claimed led to the sacking of 36 Roman cities. By the end of the year, though, constant harassment and the fatigue of his own men led Sharpor to opt for withdrawal back to Sassanid territory. Laden with captured slaves and treasure, the Sassanid king was feeling pretty good about himself, and likely thinking that the next time he marched west, he might just make a play at staying permanently.

Which brings us to Lucius Septimius Odinothus, and the city of Palmyra. Palmyra was an oasis town located in the deserts between Persia and Syria, and it served as a key link in the east-west trade routes, acting as the last way station on the northern leg of the Silk Road. Not only did the city's isolated location allow it to grow wealthy from the duties and taxes levied on traders who had no other option but to pass through Palmyra, but it also allowed them to run a protection racket, supplying local muscle to help ward off desert thieves who might set upon an unprotected caravan. That there was something of a revolving door between the desert thieves and the local muscle is of course neither here nor there.

Palmyra's location out in the middle of the desert also allowed it something that most cities in the ancient world had long since lost, independence. The age of the city-state had long ago given way to the age of the multinational empire, while Palmyra lay out in a nebulous gray area between Rome to the west and Persia to the east. As such, it was often claimed by both, but controlled by neither. As Parthian power had waned though, Palmyra had more and more come into the Roman sphere, and many of its leading citizens had also been made Roman citizens. Emperors understood the economic importance of the oasis city, and wanted to make sure that the rulers of Palmyra were given every privilege and perk of status enjoyed by the leading men of Rome. As his name suggests, the family of Lucius Septimius Odinothus had been granted citizenship by Septimius Severus around the turn of the third century, and though they were not technically Roman senators, they were recognized as being of senatorial rank, in the economic sense of the term, if not in the strictly political sense. By the 250s, Odinothus was the leading man of Palmyra, and acting as the city's chief executive. He had close ties to Rome, but the growing power of the Sassanids had left him and his city in a precarious position.

The Romans were content to let Palmyra enjoy its nominal independence, as long as the trade routes continued to function and the taxes on Roman merchants didn't get out of hand. But sharp work seemed an altogether more ambitious sort. Odinothus had been worried for some time that the Sassanids would attempt to take over direct control of Palmyra, and with the Romans being dealt several defeats in a row at the hands of the Persians, his anxiety had to have grown immeasurably by the time Valerian was captured in 260. Some sources claim Odinothus made overtures to Sharpur, attempting to forge an eastern-looking alliance, but that the Sassanid king had rejected the notion of a treaty, clearly indicating that a takeover of Palmyra was coming down the chute. But others reject the notion that Odinothus made any attempt to bargain with the Sassanids, and that from the get-go, he believed that the fortunes of his city were best served when they were tied to the fortunes of Rome. Whatever the underlying reasons, when Sharpur made his way back to the east in 260 laden with treasure, he was met by an army raised and led by the Palmyrene prince. The result of the meeting was a complete rout of the unprepared Sassanid army. Sharpur thought himself a thousand miles from anything resembling a real threat, and was as surprised as his men to find himself suddenly fleeing back to Ctesiphon after being smacked around by some cobbled-together army led by an obscure Palmyrene.

By putting Sharpur to flight, though, obscure Odinothus vanished forever, replaced in the minds of east and west alike by legendary Odinothus. Legendary Odinothus went on to become one of the most unique figures in Roman history. His capital was Palmyra, technically beyond the Roman frontier, and though he held Roman citizenship, he was still considered by most Romans to be a barbarian. A smart barbarian and a cultured barbarian, but a barbarian nonetheless. There is always something to be said for promoting men of merit, wherever you can find them, and any time the Romans faced a dire crisis, they always did well when they laid down their traditional class biases to elevate the most capable man to lead them out of danger, whoever he might be and wherever he might come from. But the rank, power, and status gained by Odinothus was something altogether different. After defeating the Sassanids, this foreigner essentially leased the eastern provinces from its Roman owners. He never held the title, but he lived in the house and he called the shots. All with Gallienus' technical blessing.

Were he not viewed as the only thing standing between the Romans and a complete Sassanid takeover, nothing even remotely close to this arrangement would have been possible, and Odinothus probably would have been executed for even suggesting it. But desperate times call for desperate measures, and in these desperate times, the Romans gave themselves over to a Palmyrene prince who promised to keep the Persians at bay.

As the west was giving itself over to Posthumus, and the east was giving itself over to Odinothus, there was one other trouble spot that Gallienus faced after his defeat of the Alamanni in 260 AD. Back on the northern frontier, the troops that had been left behind after Gallienus headed to Italy following his suppression of Engenus, were dealing with a host of German tribes ready, willing, and able to overrun the Danube. As was the case with the Rhine legions, the Danube troops resented the Emperor for dashing off after deeming their problems not sufficiently dire enough to remain in country with them. Again, their resentment may not have been rational. The Emperor was after all going to defend Italy, the home province, the invasion of which probably was the most dire threat facing the Empire at that particular moment. But that didn't stop them from taking the Emperor's absence personally, and as they steeled themselves to fend off the Germans, they elevated one of their generals, a man named Regalianus, to the rank of Emperor.

As with Posthumus, the elevation was not taken by Regalianus as his cue to march on Rome and establish his authority over the capital. Instead, he took it as his cue to lead a vigorous defense of the Danube provinces, which he now considered his personal responsibility. So there were now at least three men, Gallienus, Posthumus, and Regalianus, each claiming the title Imperator, and it is possible that they were already joined by two more, the sons of Macrianus in the east. It is hard to tell when, in this mishmash of events, Quietus and Macrianus the Younger were elevated to the rank of Coagusti by the eastern legions at the behest of their father, but it probably came not long after Odinothus' victory over Sharpor. It is not hyperbole to state that at this moment, the Empire's executive leadership had never been as fractured, as local citizens and soldiers alike each looked to local commanders to see them through these dangerous times.

In Italy, Gallienus still considered himself the ultimate master of the whole Empire, and while his rivals focused on defending the borders, Gallienus focused on how to win back all that had so suddenly been stolen from him. Though the east and west would remain outside of his jurisdiction for the rest of his life, the Danube provinces were quickly brought back into the fold, as Regalianus was killed shortly after his elevation, battling a tribe of invading Germans. Gallienus immediately marched up from Italy to restore his mastery over the legion, and with the Emperor on hand once again, the legions quickly fell back into line.

One of the biggest problems facing Gallienus at this point was that events were unfolding so fast, and invasions occurring over such a wide area, that it was difficult to deploy legionary forces in a timely manner. For all his rushing about, Gallienus always seemed to be arriving too late to nip problems in the bud, and seemed to forever be showing up just in time to close the barn door after the horses had run off. This inability to efficiently reinforce hot spots, was not just increasing the amount of devastation being wrought on the provinces, but, as we have just seen, it was also leading to an exponential increase in the number of usurpers challenging his rule. But if the provincial legions could be convinced that the Emperor would be able to quickly provide help when they were attacked, Gallienus figured they would be less prone to supporting rivals. Right now though, the legionary apparatus was too cumbersome to move quickly from one zone to another. So Gallienus hit upon an idea that though it would not become official Roman policy for another generation, it would one day become a staple of Roman defenses in the 4th century. The Mobile Cavalry.

Up until this point, cavalry units were attached to infantry legions, and they would all move around and fight together. But as quickly as the Roman legions could move, a couple of thousand foot soldiers are never going to be able to move as fast as a couple of thousand horsemen. What Gallienus did was collect all the various cavalry detachments and mass them together into a single force that would be run by a single commander and be answerable directly to the Emperor. From this point on, wherever there was trouble, the Emperor would order his mass cavalry unit to the scene, and in many cases, their mere presence would be enough to deter invaders. Not only did this cavalry serve as an excellent deterrent, it also served as a good psychological connection between the far flung provincial legions and their Emperor. They no longer felt they were being left to fend for themselves out on the frontier. Maybe the Mobile Cavalry wasn't based in their territory, but when they needed help, help was on the way.

Gallienus strategically based this new force in the city of Milan, where they could keep an eye not just on posthumous, whose long term ambitions were at this point unknown, but also on any Germans thinking about crossing through the Alps into Italy. They were also near enough the Danube frontier, that if the Goths got itchy feet, and they would over the next decade, the Mobile Cavalry could spring into action and be on the scene in no time. It was an idea born of the particular circumstances Gallienus was facing at the time, with domestic revolts and foreign invasions cropping up all around him. But in time, the wisdom of a permanent mobile defense force would become obvious. Times had changed. Simply posting legionary garrisons along the frontier was no longer sufficient to ward off foreign threats to the Empire.

There are many reasons why Gallienus' reign is seen as a period of transition, and the Mobile Cavalry is just one obvious example. Next week, we'll get into a few more examples. In particular, Gallienus' relationship with the Senate, and the growing divide between a political career and a military career, would lead to the armed forces finally becoming a completely separate branch of the state. Rome had always intermingled its political leaders with its military leaders, and indeed, the most important function of the consul had, once upon a time, been to act as the commander-in-chief of the army. The days of combining military and civilian careers, though, was about to end, as the professionalization of the army, long established among the rank and file, was now finally reaching to the top of the chain of command. Henceforth, generals would now be generals, and politicians would be politicians, and only in the person of the Emperor would they ever meet again.