The God Emperor who saved Rome - for a time
Review of Diocletian and the Roman Recovery by Stephen Williams
Beyond his persecutions of the Christians, the Emperor Diocletian is hardly known. If nothing truly dramatic occurred during his reign, some catastrophe that a narrative could be built around, he was a fundamental innovator in governance, administration, and military strategy. Indeed, he saved the Roman Empire after a 50-year period of disintegration and chaos. He also established the divine rulership that served as a template for kings in the Medieval Ages. I believe his accomplishments are essential to understanding the history that followed, to the present day.
The book starts at the tail end of the golden age of the Empire, during the relatively peaceful, populist reign of Marcus Aurelius. He had stabilized Rome with a straightforward perimeter defense against the German tribes, with outposts that protected the borders against barbarians that refused to submit to the Roman system of governance or were out of its reach. The barbarians at that time were essentially small tribes that were poorly organized and easily pitted against each other. Furthermore, since the time of Augustus, administration remained haphazard, the privilege of senators closer to Rome and military men on the fractious outer reaches. Administrative successes were a mix of military competence, aristocratic privilege, and luck.
After the catastrophic reign of Commodus (r. 177-192 CE), the Empire entered a period of accelerating chaos. With the military and the Praetorian Guard predominant, virtually every passage of political power was resolved by civil war – at least once a year, sometimes more. Moreover, as barbarian tribes were mastering Roman military tactics; they were organizing into larger, more proficient forces that could mount complex military strategies, which many of their leaders had studied as Roman mercenaries and clients. Finally, Roman society and the economy were increasingly dysfunctional: taxes were haphazardly collected, trade shrunk by more than 75%, and the cities were degenerating from vital centers into dilapidated backwaters. Taken together, the end of Rome had become a distinct possibility. The borders were no longer secure, necessitating desperate measures to defend the core of the Empire, essentially by brutal requisitions from those near the field of battle by fiat and circumstance, impoverishing local populations and eroding the polity and community belief in the state.
The military coped as best it could. Key to this time was the rise of a new elite, the Albanian military men. Unlike the educated Roman aristocracy, they were pure military, lacking classical finishing and manner, but tuned in to the necessities of permanent mobilization on a war footing. They were disciplined and hardened to the realities of power after 50 years of grinding uncertainty. This was where Diocletian came from, observing carefully and awaiting his opportunity to do better as he rose to generalship. Once declared emperor by his troops, he fought a brutal civil war and almost lost.
To rule with stability in both succession and across the massive Empire’s territories, Diocletian created the tetrarchy, with co-emperors (Augusti in east and west) and two junior emperors (Caesars). He did this to consolidate power, dividing responsibilities geographically and by specialty. It was a shrewd move, freeing him from the necessity to scramble to answer every crisis as they occurred in person. This enabled him to think strategically and longer term. It took, of course, extraordinary political skills to make the system work, not only in choosing the right partners, but in keeping them happy in their careers as well as legitimate in the eyes of all citizens. He also transformed the image of the Emperor into a more isolated individual, with special links to God in the mold of the "oriental despot"; in this way, he was Zeus and his co-Augustus was Herakles, to whom absolute loyalty was sworn. It was a model of divine legitimacy that Constantine (also an Albanian) would shrewdly exploit when he converted to Christianity, as would later Medieval kings.
The tetrarchy, as the book demonstrates, only just scratches the surface of how Diocletian wielded power. He also professionalized the administration of the Empire with the creation of a bureaucracy, a more equitable tax system, and a revamped military strategy. In the process, the senatorial aristocracy lost the last vestiges of its privileges, opening the bureaucracy to talent, complete with career routes but also the systematic development of specialties for the first time (in the West, at least). I was simply astonished at how modern his ideas appear, though also somewhat skeptical of Williams’ unalloyed enthusiasms.
The most important part of this was the separation of military from other administrative functions. Most importantly, the Praetorian guard lost its political role. This was an innovation so fundamental that it cannot be overestimated, particularly in light of the political risks involved. Whereas competent administration had been extremely rare in the confused mixing of aristocratic privilege, military position, and political career of Augustus’ imperial system, it now became the province of professionals. It also added stability because of the stricter division of labor – lacking experience, military men were less likely to enter politics via coup. Finally, specialization encouraged the development of expertise for the bureaucracy. While this later led to the origin of the term "byzantine" to connote excessively bureaucratic processes, it was also a necessary step and vital to the survival of the Empire.
On the tax front, Diocletian began a comprehensive regime of census-taking as a way to determine what citizens "owed" in taxes. Essentially, a percentage of labor was required of everyone, as determined by the needs of the Empire as an integrated system. The burden could be heavy, depending on circumstances, but everyone knew what they had to pay and that they shared it. This served to legitimize the Empire, enabled people to plan again, and contributed to the revival of the economy, though the population decline necessitated the use of German troops. Now, this makes for some pretty dry reading at times, but again, it is an innovation so far-seeing that it is a wonder, truly a work of political genius.
Finally, the military dimension. Building on the mobile strike force that his predecessors had pioneered, Diocletian moved the military bases from the periphery to strategic, fortified points – the forerunner of the chateaux forts that emerged in the 9th century – deeper within the Empire’s borders, where cavalry could service multiple points in a matter of days rather than weeks or months. The strong forts were staffed with disciplined professional forces, real military men like Diocletian. Nearer the borders, Diocletian developed a kind of peasant army, the cannon fodder that would absorb the immediate brunt of attacks and hence allow the mobile units the time to respond. This system worked over the next 100 years.
Of course, in spite of these innovations, there were limits to Diocletian's vision and accomplishment. Like many military men, he viewed the economy as an annoying complication and attempted to set up a command economy, setting prices by decree. It was an embarrassing failure. He also waged, perhaps reluctantly, wars against the monotheistic religions, starting with the Manicheans, who were viewed as agents of the Persian Empire; because Christians refused to swear personal allegiance to the God Emperor, the fight with Christianity originated from similar fears of revolutionary subversion. Far worse, his tetrarchy did not survive him. Not only did one of his original co-emperors initiate a civil war at the moment that Diocletian retired to a massive castle in Split, where he was an impassive and impotent observer, but the sons of original tetrarchy members (Constantine and Maxentius) fought each other and destroyed the system entirely.
I have few criticisms of the book. It may be focused too tightly on Diocletian, attributing too much to his foresight. He also goes a bit easy on his role in the persecution of Christians, placing the blame on a co-emperor when Diocletian was clearly the top dog.
Though Williams is not a professional academic, his book is a masterpiece of popular history. If at times the prose is somewhat spare, the book is so dense with ideas and subtlety that it is a constant delight.
Below is an image I had to add. It’s apparently a Georgian icon of St. George (ca. 10th century), the martyr whose death Diocletian is purported to have ordered. Normally, St. George is depicted killing a dragon, not Diocletian.