Third Century AD - the Empire is Never Reunited

[Paul Elliott]

I'm working on a short project that sketches out a possible alternate historical outcome for the third century. The empire has been split three ways by the Gallic empire and Palmyra, the emperor has been captured and imprisoned, invasions are frequent and almost overwhelming. If there had been no Claudius II or Aurelian to restore the empire, what might have occurred?

One possibility I am pondering is a more permanent split; like the Gallic empire, regions look to their own defensive interests. Perhaps the fault lines occur in a similar manner to those imposed by the Tetrarchy at the end of the third century, but of course, in this alt-history, those districts are now separate independant Roman empires.



To the west, the Gallic Empire, Britain, Gaul, the Rhine frontier, perhaps minus Spain. In the east, Palmyra, with Syria, Egypt, Cyrenaica and Asia Minor. Centrally, there would be Pannonia, Greece and the Balkans, fighting fiercely against the Goths and Germans. Italy retains North Africa, Sicily and Spain. I would imagine threats from beyond the borders being able to be beaten back, since local defence might make up for the long-distance rule and poor reaction times from Rome. Things would not remain static of course, just as the Successor states to Alexander's empire began to fight and struggle, so might these Roman empires.

AS for the role of Sassanian Persia or the rise of the Goths ... I don't know. Perhaps it is still too early in the timeline for mass Gothic settlements, or adoption of tribes as mercenary forces, then again, with the new competition between Roman empires, use of Goths as go-betweens and mercenary proxies in the late third century might actually fit with the politics of the age. As Theodosius realised, the best way to deal with a Goth is to turn him around and point him in another direction.

This isn't an indepth project, just a short sketch ... but I'd still be interested to hear any other theories, or changes to this one!

[Flavivs Aetivs]

Honestly, in a nutshell, I'd have to say Sassanid Persia would have overrun the Palmyran empire by the beginning of the 4th century, and would then invade Greece. The Roman Army had to increase significantly in size to compensate for the rise of the Sassanids. With multiple borders throughout the Empire, those forces have to be split up. Eventually one would still overrun the other 2 Roman empires, but the Sassanids would eventually permantly absorb Roman holdings in Asia and Egypt.

[Paul Elliott]

That sounds plausible to me, Shapur I showed how he could push his forces deep into Asia Minor.

[Robert Vermaat]

I disagree. The Levant perhaps, after Palmyra the next logical step would have been Syria, Palestine, then Egypt. After that, I really doubt if the persians would have been able to sustain any occupation. The same think happened after the rise of the Ummayads - after losing the provinces mentioned above, and even though weakened severely by internal and external wars, the Romans were able to hold on to Asia Minor for centuries.

I think that the main reason for the in-fighting between west and east was Illyria, and the very bad way in which the successions etc were dealt with. the Roman Empire was never split, after all, that our modern take on things. It was only administratively reorganised, and unfortunately the heads of all parts could 9due to accession being a shambles) claim rights over other parts. If that had been taken care of beter, Constantine could never have ruled the east, Stilicho could never have coverted Illyria.

What may have been the result of a real split? Imagine that no ruler of any part would have coveted all (it's hard, i know), I think Italy would have been able to hold on to Spain and Africa, but Gaul, being on the front of eager Germans, I don't know. Would they have had a more secure economic base to pay for the military? Possible better than they would have had in real history. maybe they would have been able to take Gaul and Italy, as we've seen the Franks attempt during the 6th c.
The Greek provinces would probably have been reorganised as the Empire during the 6th and 7rth c., with thrace being a factor of strength. I think they would have managed to keep (or throw) the persians out of Asia Minor.

[Flavivs Aetivs]

Illyria was wierd about that, it seems that it was split from where the river save begins down to the coast north-west of Dyrrhachium. It changed hands between East and west it seems depending on who ruled it - under Aetius it was in the west, but Sirmium ended up Eastern Owned by 440, and later it went to the east under Julius Nepos.

[Nathan Ross]

the Roman Empire was never split, after all, that our modern take on things.

I agree - there was no territorial division under the Tetrarchy. In fact the Tetrarchs were very keen to stress the unity of their realm on coin mottos and so on - just as their statuary represented them as looking more or less identical, they were four heads with one body, so to speak. It was only later, during the civil war, that the territories of the empire were divided under rival emperors, and even then not for long...

Looking back to the third century, I suspect that, whatever the difficulties of the age, the central core of the empire still had the power and the will to exert itself over the rest - it just took a strong enough leader. Aurelian did this, and Diocletian cemented it - if these two did not exist, probably the competition of Roman rule would have thrown up some suitable contender in due course. The continuing east v west imperial contests of the 4th century demonstrate the ongoing ability of single commanders to defeat regional revolts.

I'd agree, too, that the power of Persia could be overestimated - they had their own border and succession problems, which would have stopped a relentless takeover of a weakened Roman east. Even if they'd grabbed Palmyra, the next Roman invasion (both Carus and Galerius showed that such expeditions from a Danubian powerbase were more than possible, and successful too) would have pushed the Persians back again.

The situation in the west might have been more secure - the repeated attempts of the Gallic provinces and Britain to support usurpers suggests that many in that part of the world could easily accept a regime separate from Rome. But if the centre was really too weak to retake the west, it surely wouldn't take long for the west itself to reconquer the weakened centre. This is, after all, more or less what happened under Constantine from 312 onwards - a 'Gallic' imperium moving first into Italy and then eastwards to unite the empire.