Eugenius and Arbogast win the Battle of the Frigidus?

[Vinization]

The Battle of the Frigidus, which happened in September 394 AD, pitted the forces of Eastern Roman Empire, led by emperor Theodosius I, against those of its western half, led by emperor Eugenius and magister militum Arbogast, who was the power behind the throne. IOTL Theodosius won the battle, and although he would die a year later, his triumph sealed the end of the abortive pagan revival that took place under Eugenius' brief reign, which included the restoration of the Temple of Venus and Roma and the Altar of Victory, along with the appointment of a pagan prefect of Italy.

So what if Arbogast and his puppet emperor won? According to Wikipedia and Kings and Generals (are they a credible source?), Theodosius seemed to be on the ropes after a disastrous frontal attack in the first day of fighting, until a detachment of Western soldiers who were supposed to attack his army from the rear deserted to his side. Suppose they don't desert, for whatever reason, and the Eastern army gets smashed into pieces the next day.

What could be the consequences of such a development? IOTL the Visigoths fought on the Eastern side and suffered the brunt of the casualties, with Alaric using that as a pretext to launch the campaign that eventually led to the sack of Rome in 410 AD. They're bound to suffer even more losses in a defeat, so could that be enough for them to not be a factor for either empire to worry about? Would the Western Empire be better suited to deal with events such as the crossing of the Rhine without losing such a massive battle (both armies had around 50.000 men)? Could it become a refuge for pagans fleeing from persecution in the east?

How would the Eastern Empire be affected? Theodosius died only a few months after the battle IOTL, so even if he isn't killed in action or executed he probably won't live much longer. Could there be a civil war or at least some kind of turmoil? The Huns attacked Anatolia and Syria in 395, so could they cause more problems there?

 

[Fabius Maximus]

The Western Empire is almost certainly in better shape, since it will have lost fewer soldiers in a victory than it did in defeat. The East, OTOH, would be in worse shape, although since its core territories weren't open to barbarian incursions in the way the West's were, it will probably be in a better position to weather its difficulties, particularly if the Goths are too weakened to do anything.

As for the Western "pagan revival", I suspect that's kind of over-hyped TBH. Eugenius and Arbogast might have been more amenable to pagan practices than Theodosius, but that would probably cash out as restoring the legal privileges of certain pagan cults and priesthoods which had been stripped from them under Gratian. A Julian-style repaganisation programme almost certainly wasn't on the cards, and would be unlikely to succeed if it was tried.

 

[Vinization]

As for the Western "pagan revival", I suspect that's kind of over-hyped TBH. Eugenius and Arbogast might have been more amenable to pagan practices than Theodosius, but that would probably cash out as restoring the legal privileges of certain pagan cults and priesthoods which had been stripped from them under Gratian. A Julian-style repaganisation programme almost certainly wasn't on the cards, and would be unlikely to succeed if it was tried.

I agree that it seemed to be more of an attempt to get financial backing from pagan senators rather than a genuine restoration, but was there a chance it could've snowballed into something bigger? What was the religious makeup of the western empire like at this time?

 

[Fabius Maximus]

I agree that it seemed to be more of an attempt to get financial backing from pagan senators rather than a genuine restoration, but was there a chance it could've snowballed into something bigger? What was the religious makeup of the western empire like at this time?

Not sure about the religious makeup as a whole, but the upper classes were mostly Christian by this point, IIRC.

I'm not sure it would snowball, really -- Julian had tried an actual pagan restoration a few decades earlier, and it met with little enthusiasm, so I doubt Eugenius' restoration in less propitious circumstances would have a bigger impact.

What you might get, though, is a stable pagan minority -- say, with 3/4 (or whatever) of the upper classes being Christian and 1/4 being pagan, with this ratio remaining relatively stable over the long term. IOW, Christians would still be the dominant group, but pagans would be a significant and visible minority, with some impact on the overall culture of the Roman elite.

 

[Gloss]

Julian had tried an actual pagan restoration a few decades earlier, and it met with little enthusiasm,

If Constantine died a few years into his reign after the Edict of Milan either in a civil war or against foreign enemies Christianity wouldn't have grown virtually at all(in case of a death during a post-Edict of Milan civil war it's possible Licinius would have outlawed it again).

 

[Fabius Maximus]

If Constantine died a few years into his reign after the Edict of Milan either in a civil war or against foreign enemies Christianity wouldn't have grown virtually at all(in case of a death during a post-Edict of Milan civil war it's possible Licinius would have outlawed it again).

True, but by Julian's time that ship had sailed, and I can't imagine a repaganisation attempt being any more successful thirty years later when Christianity's had a whole extra generation to bed in.

 

[Some Bloke]

Arbogast sounds like a Chaos Warlord from 40K.

 

[Vinization]

Pivoting to the east for a moment, is it possible for the Sassanids to smell blood in the water and invade Syria once they get news of Theodosius' defeat? They went through a time of instability after Shapur II if Wikipedia is to be believed, with the following shahs having a tendency to be killed by the nobility. Could Bahram IV, whose reign was mostly uneventful save for a Hunnic invasion of Mesopotamia in 395 (concurrent with their incursions into Anatolia and Syria), decide that looting the riches of Antioch and other important Roman cities would strengthen his position at home?

 

[SlyDessertFox]

The Western Empire is almost certainly in better shape, since it will have lost fewer soldiers in a victory than it did in defeat. The East, OTOH, would be in worse shape, although since its core territories weren't open to barbarian incursions in the way the West's were, it will probably be in a better position to weather its difficulties, particularly if the Goths are too weakened to do anything.

As for the Western "pagan revival", I suspect that's kind of over-hyped TBH. Eugenius and Arbogast might have been more amenable to pagan practices than Theodosius, but that would probably cash out as restoring the legal privileges of certain pagan cults and priesthoods which had been stripped from them under Gratian. A Julian-style repaganisation programme almost certainly wasn't on the cards, and would be unlikely to succeed if it was tried.

I want to expand on this a bit into what the immediate impact in the east is. Theodosius is either dead immediately or dead soon thereafter anyway, so the east has a bit of an issue-Eugenius under the tutelage of Arbogast is officially the senior emperor, but the court in Constantinople is obviously made up of Theodosius's men and Arcadius is Theodosius's immediate successor in Constantinople (I assume, at the very least, Honorius, being elevated by Theodosius to the rank of western Augustus, cannot be allowed to rule in this scenario for obvious reasons). Arbogast/Eugenius have a few options here:

1.) They could try reconciliation, recognizing Acadius as the legitimate junior emperor in the east, and offer an olive branch to the existing eastern court. This is the less flashy, but easiest route-they can claim that they always recognized Theodosius's legal claim, but that he started an unjust war to overthrow Arbogast based on the mistaken assumption that he had killed Valentinian, and Arbogast/Eugenius have no intention of imposing their will or nullifying Theodosius's rule. This of course carries its own issues as there will still be an air of distrust between the two courts, but the east might be too busy with their own issues and internal power struggles (Arcadius is, after all, as we know basically a figurehead emperor, destined to be controlled by various jockeying factions).
2.) They try and impose their own successor on the east. They would have to be incredibly careful here, because obviously the eastern court is uninterested in having a new emperor imposed on them by those that just fought a civil war with Theodosius. Unfortunately it does not appear we know much about Eugenius beyond being an influential Roman and a Christian-little about his family, for instance, that could help us figure out who he might find suitable as a replacement for a co-Augustus.

Finally, there is no guarantee that Arbogast and Eugenius stay on good terms with each other, and a decent chance they Eugenius ends up scheming to replace Arbogast (much in the way Leo I outmaneuvered Aspar.

Pivoting to the east for a moment, is it possible for the Sassanids to smell blood in the water and invade Syria once they get news of Theodosius' defeat? They went through a time of instability after Shapur II if Wikipedia is to be believed, with the following shahs having a tendency to be killed by the nobility. Could Bahram IV, whose reign was mostly uneventful save for a Hunnic invasion of Mesopotamia in 395 (concurrent with their incursions into Anatolia and Syria), decide that looting the riches of Antioch and other important Roman cities would strengthen his position at home?

During this period the Sassanians were more interested in cooperating with the Romans on protecting the Caucusus from Hunnic invasions.

 

[Vinization]

Could the evacuation of Britain be prevented ITTL?

During this period the Sassanians were more interested in cooperating with the Romans on protecting the Caucusus from Hunnic invasions.

Would it be possible for them to get greedy, though?

 

[raharris1973]

Could we get the Huns to stick around and reinforce their invasions of west Asia, and never end up doing much invading of European Rome?

 

[Vinization]

Could we get the Huns to stick around and reinforce their invasions of west Asia, and never end up doing much invading of European Rome?

Maybe, since the ERE would need to raise a new army from scratch right as they're moving down the Caucasus. I don't think it's likely, however, since the Sassanids could help the Romans kick them out... or smell blood in the water and take whatever territories the Huns capture for themselves.

 

[raharris1973]

Maybe, since the ERE would need to raise a new army from scratch right as they're moving down the Caucasus. I don't think it's likely, however, since the Sassanids could help the Romans kick them out... or smell blood in the water and take whatever territories the Huns capture for themselves.

Just would be neat to see the Huns take down the east, even if they crossed from Anatolia to Thrace, and if it ended up attracting the Goths, Burgundians, and other Germanic on the move to the eastern empire locations like the Balkans, Anatolia, possibly Levant and Egypt to resettle instead of them going across the Alps to Italy or the Rhine to Gaul and Spain.

 

[Vinization]

Just would be neat to see the Huns take down the east, even if they crossed from Anatolia to Thrace, and if it ended up attracting the Goths, Burgundians, and other Germanic on the move to the eastern empire locations like the Balkans, Anatolia, possibly Levant and Egypt to resettle instead of them going across the Alps to Italy or the Rhine to Gaul and Spain.

I agree that having the East collapse while the West survives and eventually prospers is a very interesting scenario.

 

[Silver01]

Pivoting to the east for a moment, is it possible for the Sassanids to smell blood in the water and invade Syria once they get news of Theodosius' defeat

Considering that the Huns raided deep in to the empire in 395 invading the Romans in 394 would mean a very quick peace and or a more devasting series of raids

 

[Vinization]

Considering that the Huns raided deep in to the empire in 395 invading the Romans in 394 would mean a very quick peace and or a more devasting series of raids

The Huns attacked both empires in 395, perhaps they could focus more on the ERE ITTL.

 

[Silver01]

The Huns attacked both empires in 395, perhaps they could focus more on the ERE ITTL.

The Huns attacked the ere from Thrace the same year they attacked the Persians with the Romans and Persians fighting each other in Syria the Huns can sack Anatolia and nother mesopotamia with out much trouble hence why it's far more likely the sasnaids make peace with the Romans in fact a worse raid would mean a bigger fear of the Huns

 

[SlyDessertFox]

The Sassanids are also going through a period of (relative) instability during this time, which was one of the reasons their relations with the Romans were so cordial.