What if the Western Roman Empire survive and the Eastern Roman Empire fell?

[Sturm1820]

Lately I have been researching the Western Roman Empire and I have been making a mapgame of the usurpation of Magnus Maximus and I have asked myself the following question: What would have happened if the destinies of the West and East were reversed? that is, the Western Roman Empire manages to maintain its territories for a few more centuries while the East falls to the Goths and Vandals (and of course the Sassanids)

So what would be the effects of a surviving Western Roman Empire? And I don't mean a dying state retained in Italy and Africa, but maintaining its territories from Britannia to Germania and Illyria. Some may want to talk about the plausibility of this, but for the moment I would like to know the effects of this, certainly, peoples like the Franks and Visigoths no longer settle in Gaul and Spain, bringing various butterflies with them, what would happen to Germany? Magna in this scenario? Would independent kingdoms develop that would take advantage of the weakening of the West over time? Another thing that I wonder is the effects in the East, if some migrations are not diverted and settle in the East, how and where could they settle? Another question that arises to me is the Christianization of Eastern Europe, I think it would be a matter of time until missionaries arrive, but I see several butterflies here. Finally and in summary, how would the survival of the Eastern Roman Empire affect the events that took place throughout the 6th, 7th and 8th centuries?

 

[Sturm1820]

No one?

 

[athgtq16129]

Here is some old material related to this topic:

AH challenge: Western Roman Empire survives, Eastern Roman Empire falls

Your challenge, should you choose to accept it, is to have the western half of the Roman Empire survive while the East falls (so you have to switch their fates).

www.alternatehistory.com

AHC: Reverse the fates of Eastern and Western Rome

How would you make is so that the Western Empire survives, whilst the Eastern one falls, lets say by roughly 500AD.

www.alternatehistory.com

Switch the fates of the Western and Eastern Roman Empires

What is the best POD that will have the fates of the Eastern and Western Roman Empires switched, where the east falls to barbarian invasions and the west holds on to most of their territories?

www.alternatehistory.com

AHC: Switch Eastern and Western Roman Empire

Switch the histories of East and West Rome. Have the Western Empire rule onward for centuries while the East descends into chaos and war before stabilizing far down the line.

www.alternatehistory.com

AHC: Have the Western Roman Empire Survive and the Eastern Half Fall

Find a way to preserve the Western portion of the Roman Empire survive but the Eastern Half collapse. Probably ASB at best.

www.alternatehistory.com

Western and Eastern Roman Empire AH Challenge

Create a scenario where the Eastern Roman Empire collapses in the late 5th century and the Western Roman Empire survives until round about the 15-16th century.

www.alternatehistory.com

WI Attila invades Eastern Roman Empire instead of Western?

In OTL Eastern Emperor Theodosius II accepted a tribute to Attila purportedly 300 kg (700 lb) of gold) in order to stop the Hunnic raids in Thrace and the Balkans... His succesor Marcian however refused to pay this tribute but Attila was too busy in the West to deal with Marcian... WI Attila...

www.alternatehistory.com

https://www.reddit.com/r/AlternateHistory/comments/vsnugc

 

[Lacktoastandtolerant]

One of the things with this is, In OTL, the Eastern Empire had a number of advantages helping its survival while the Western Empire had a number of disadvantages. Its far from impossible to swap the fates of the East and West, and there's multiple ways it could potentially plausibly be done, but it could need some potentially big changes vs OTL. And its hard to just generally say "this is what would happen if the West survived and the East fell", because a lot of what would happen would depend on how and why things went differently - and one could come up with different ideas for survival which could lead to rather different outcomes

Just as one example, one may imagine a scenario where the Western Empire is more accepting of immigration/refugees, figuring that accepting settlers from outside the empire would help alleviate issues of population decline and provide more military recruits, while also deciding to just properly pay the immigrant troops it recruited, rather than running into the issues of OTL where it often refused to pay troops - leading to conflicts with the foederati that could have cost the empire more in damages than the withholding of pay brought. Perhaps this Western Empire also manages to deal with some of the issues of imperial overstretch and problems with governing its wide expanse by granting some local autonomy to various parts of the empire with some sort of "foederal" arrangement, perhaps one that goes all the way to basically developing something like medieval feudalism, or perhaps something that strikes a balance between the medieval feudal fragmentation of state authority on one hand and the very centralized previous imperial authority on the other hand. And meanwhile in the East... idk, maybe some combination of "more religious strife (between various sects of Christianity", "more successful Sassanids, somehow", and perhaps "a West that's more successful at defending against the migrants who intended to invade (Huns, etc) rather than just immigrate peacefully (Goths, etc) ends up diverting more of the former towards the East", and maybe also throw in some dynastic civil wars, and you can get the East to fall earlier. In that scenario, you could even end up with the Franks and Goths still settling within the Roman boundaries

And another potential scenario for increasing the longevity of the West could be for the Vandal destruction-via-espionage of the Western navy in Spain to be prevented (perhaps the Romans have better security in the area or just get lucky and catch wind of the plot before it succeeds) and then Emperor Majorian is able to successfully conquer the Vandal Kingdom in Africa. Then, with the momentum from this victory, and having basically secured the southern flank of the Western Empire, he's able to turn towards fighting to restore and expand Roman authority in other parts of the West as well as continuing attempts at reforming and strengthening the Empire's domestic institutions, while using prestige from his previous victories and the (in this scenario) victory against the Vandals to avoid getting deposed and killed by Ricimer and the aristocrats. Its believed Majorian was born "after 420", and he died in 461, so in a "Majorian survives and succeeds in his campaigns against the Vandals" scenario, Majorian could have a few more decades to keep up his attempts to restore the Western Empire and centralized authority, so long as he could figure out how to keep avoiding getting deposed and killed by Ricimer and the aristocrats

These different scenarios could lead to rather different Western Empires, and one may imagine various scenarios where the Eastern Empire falls in various different ways too. So its hard to say much for sure, when we don't know how the West survives and the East falls

 

[CommieScum]

So firstly, you ofcourse route the Germanic tribes to the East instead of the West, following behind the Goths. I think Britain would also have to fall at some point so that the West isn't too overextended. The Balkans would be completely overrun, Anatolia too, its uncertain to what extent to Sassanids come in.

Where things get interesting is when the second wave of migrations begin. Where do the Lombards go? Where do the Slavs? And perhaps the Arabs later on.

Remember that in OTL, despite the East's initial survival the Slavic people completely overrun the Balkans- It was only retaken gradually over the course of centuries and that was not an inevitability.

What the West needs to continue to survive, is a solid base that is invulnerable and reliable. For the East, this was Constantinople, guarding Anatolia from conquest. There are a few possibilities in the West. I think Ravenna perhaps, or more extremely Carthage and North Africa.

Secondly widespread reform, though I am not well enough informed to be sure what form this would take. Perhaps you would need a Justinian like figure here.

Christianity is going to also be a factor. In OTL, I believe Arianism was quite prevalent in the West, especially among the Germanic tribes. It might be a factor in the integration of the tribes that still come in or are within the Empire's borders such as the Franks.

 

[Galba Otho Vitelius]

One thing that has always struck me is that China after the fall of the Jin Dynasty, during the northern kingdoms and southern dynasties period, had exactly the opposite dynamic. Chinese dynasties with a valid legal claim to be the continuation of the Jin continued in the less populated, recently developed south. The north, which had been the center of Chinese civilization, saw an array of "barbarian" dynasties which underwent various degrees of sinification. Eventually a northern dynasty conquered the whole thing and became the Sui.

Its not quite the same in the Mediterranean, because the western provinces were not at a disadvantage to the east in terms of population, just in the ability of the government to gain access to taxable wealth. And even during Roman periods, the western army was considered to be better than the eastern one. It is actually surprising that the Roman empire was not unified by one of the western warlords. The Romans also had a serious challenge on their eastern frontier, in the form of first the Sassanians and then the Arabs, not to mention the Huns and Avars, but this also makes it surprising that it was not reunified from the West. The western provinces must have gotten seriously screwed up in some irreparable way.

An eastern empire in the state of collapse would likely lose Egypt and Syria to either the Persians or the Arabs (and the Arab dynasty would be something like Palmyra, not the Caliphate). A unified Western empire would likely be much stronger than IOTL, which implies both a competent ruling dynasty, and the ability to tax the wealthy landholders and ensure that any Germans incorporated into the army are assimilated. Such an empire would take over whatever central authority is left from the Eastern empire. ITTL Justinian could well be the Western empire, he was born to a Latin speaking family in the Balkans, where a stronger Western empire would retain influence.

The OTL eastern offensive into the Western Mediterranean was always handicapped in that the strategic priority for Constantinople had to first be defense against the Persians and the Avars. A TTL Western empire going the other way would not have this handicap, and I am proposing they take over the OTL Byzantine areas, not Syria and Egypt.

 

[Galba Otho Vitelius]

One thing that has always struck me is that China after the fall of the Jin Dynasty, during the northern kingdoms and southern dynasties period, had exactly the opposite dynamic. Chinese dynasties with a valid legal claim to be the continuation of the Jin continued in the less populated, recently developed south. The north, which had been the center of Chinese civilization, saw an array of "barbarian" dynasties which underwent various degrees of sinification. Eventually a northern dynasty conquered the whole thing and became the Sui.

Its not quite the same in the Mediterranean, because the western provinces were not at a disadvantage to the east in terms of population, just in the ability of the government to gain access to taxable wealth. And even during Roman periods, the western army was considered to be better than the eastern one. It is actually surprising that the Roman empire was not unified by one of the western warlords. The Romans also had a serious challenge on their eastern frontier, in the form of first the Sassanians and then the Arabs, not to mention the Huns and Avars, but this also makes it surprising that it was not reunified from the West. The western provinces must have gotten seriously screwed up in some irreparable way.

An eastern empire in the state of collapse would likely lose Egypt and Syria to either the Persians or the Arabs (and the Arab dynasty would be something like Palmyra, not the Caliphate). A unified Western empire would likely be much stronger than IOTL, which implies both a competent ruling dynasty, and the ability to tax the wealthy landholders and ensure that any Germans incorporated into the army are assimilated. Such an empire would take over whatever central authority is left from the Eastern empire. ITTL Justinian could well be the Western empire, he was born to a Latin speaking family in the Balkans, where a stronger Western empire would retain influence.

The OTL eastern offensive into the Western Mediterranean was always handicapped in that the strategic priority for Constantinople had to first be defense against the Persians and the Avars. A TTL Western empire going the other way would not have this handicap, and I am proposing they take over the OTL Byzantine areas, not Syria and Egypt.

The West winning the battle of the Frigidus decisively would be a good POD. It butterflies away the Theodosian dynasty in both halves of the empire and Stilicho. The Chalcedon Council is also butterflied away.

 

[The Anglo-Dutch Union]

Perhaps this Western Empire also manages to deal with some of the issues of imperial overstretch and problems with governing its wide expanse by granting some local autonomy to various parts of the empire with some sort of "foederal" arrangement, perhaps one that goes all the way to basically developing something like medieval feudalism, or perhaps something that strikes a balance between the medieval feudal fragmentation of state authority on one hand and the very centralized previous imperial authority on the other hand.

This concept of the Roman Empire surviving as a mix between a centralised imperial state and a collection of decentralized foederati is a fascinating scenarios. To make it more interesting there could be autonomous roman ‘dux’ in the border regions

 

[NedStark]

The West winning the battle of the Frigidus decisively *with the Goth mercs accounting for the vast majority of Eastern casualties* would be a good POD. It butterflies away the Theodosian dynasty in both halves of the empire and Stilicho. The Chalcedon Council is also butterflied away.

Here is my view on this.

One thing that has always struck me is that China after the fall of the Jin Dynasty, during the northern kingdoms and southern dynasties period, had exactly the opposite dynamic. Chinese dynasties with a valid legal claim to be the continuation of the Jin continued in the less populated, recently developed south. The north, which had been the center of Chinese civilization, saw an array of "barbarian" dynasties which underwent various degrees of sinification. Eventually a northern dynasty conquered the whole thing and became the Sui.

Its not quite the same in the Mediterranean, because the western provinces were not at a disadvantage to the east in terms of population, just in the ability of the government to gain access to taxable wealth. And even during Roman periods, the western army was considered to be better than the eastern one. It is actually surprising that the Roman empire was not unified by one of the western warlords. The Romans also had a serious challenge on their eastern frontier, in the form of first the Sassanians and then the Arabs, not to mention the Huns and Avars, but this also makes it surprising that it was not reunified from the West. The western provinces must have gotten seriously screwed up in some irreparable way.

An eastern empire in the state of collapse would likely lose Egypt and Syria to either the Persians or the Arabs (and the Arab dynasty would be something like Palmyra, not the Caliphate). A unified Western empire would likely be much stronger than IOTL, which implies both a competent ruling dynasty, and the ability to tax the wealthy landholders and ensure that any Germans incorporated into the army are assimilated. Such an empire would take over whatever central authority is left from the Eastern empire. ITTL Justinian could well be the Western empire, he was born to a Latin speaking family in the Balkans, where a stronger Western empire would retain influence.

The OTL eastern offensive into the Western Mediterranean was always handicapped in that the strategic priority for Constantinople had to first be defense against the Persians and the Avars. A TTL Western empire going the other way would not have this handicap, and I am proposing they take over the OTL Byzantine areas, not Syria and Egypt.

Except that the East had massive advantages in economics, demographics and especially geography.

1) Economics: the Eastern parts of the Empire were always the richer ones with more diversified economies and greater commerce.

2) Population: it had rich provinces with massive populations such as Egypt and Syria. Anatolia is also a good source of population. Thus, it had population advantage. The East also had significant advantages in terms of fighting manpower, the biggest example is the mobs of Constantinople who were capable of literally tearing Gainas' Gothic troops apart when Gainas was trying to pull a Stilicho/Arbogast and take power (compare this to Western Roman citizens whose biggest record was attacking Gothic soldiers' wives and children during Sack of Rome). Look, the Eastern Empire was saved by its capital's mobs - this is what Majorian could only dream of.

3) Geography: the Eastern Empire was divided in half by Constantinople, an impregnable fortress. This means that barbarians could not attack the rich provinces in Syria and Egypt, while the Persians could not threaten Greece and Thrace. In contrast, in the West, barbarians could walk all the way from Northern Gaul to Italy or even North Africa.

 

[Avrorrange]

One thing that has always struck me is that China after the fall of the Jin Dynasty, during the northern kingdoms and southern dynasties period, had exactly the opposite dynamic. Chinese dynasties with a valid legal claim to be the continuation of the Jin continued in the less populated, recently developed south. The north, which had been the center of Chinese civilization, saw an array of "barbarian" dynasties which underwent various degrees of sinification. Eventually a northern dynasty conquered the whole thing and became the Sui.

Its not quite the same in the Mediterranean, because the western provinces were not at a disadvantage to the east in terms of population, just in the ability of the government to gain access to taxable wealth. And even during Roman periods, the western army was considered to be better than the eastern one. It is actually surprising that the Roman empire was not unified by one of the western warlords. The Romans also had a serious challenge on their eastern frontier, in the form of first the Sassanians and then the Arabs, not to mention the Huns and Avars, but this also makes it surprising that it was not reunified from the West. The western provinces must have gotten seriously screwed up in some irreparable way.

An eastern empire in the state of collapse would likely lose Egypt and Syria to either the Persians or the Arabs (and the Arab dynasty would be something like Palmyra, not the Caliphate). A unified Western empire would likely be much stronger than IOTL, which implies both a competent ruling dynasty, and the ability to tax the wealthy landholders and ensure that any Germans incorporated into the army are assimilated. Such an empire would take over whatever central authority is left from the Eastern empire. ITTL Justinian could well be the Western empire, he was born to a Latin speaking family in the Balkans, where a stronger Western empire would retain influence.

The OTL eastern offensive into the Western Mediterranean was always handicapped in that the strategic priority for Constantinople had to first be defense against the Persians and the Avars. A TTL Western empire going the other way would not have this handicap, and I am proposing they take over the OTL Byzantine areas, not Syria and Egypt.

Ironically the Eastern Jin Dynasty was in many ways almost identical to the Western Roman Empire, especially in regards to the inability to extract taxes. The difference was that the regime was propped up by aristocrats and their serfs who fled the North, so the aristocrats had need of maintaining a military force that could crack down on the ‘native’ Southern aristocrats and their people who could potentially revolt. Similarly their armies were almost exclusively formed from refugee communities who fled the North. When it came to the need to defend themselves, the Northern aristocrats were much more willing to contribute to the state’s defence.

 

[Avrorrange]

Here is my view on this.


Except that the East had massive advantages in economics, demographics and especially geography.

1) Economics: the Eastern parts of the Empire were always the richer ones with more diversified economies and greater commerce.

2) Population: it had rich provinces with massive populations such as Egypt and Syria. Anatolia is also a good source of population. Thus, it had population advantage. The East also had significant advantages in terms of fighting manpower, the biggest example is the mobs of Constantinople who were capable of literally tearing Gainas' Gothic troops apart when Gainas was trying to pull a Stilicho/Arbogast and take power (compare this to Western Roman citizens whose biggest record was attacking Gothic soldiers' wives and children during Sack of Rome). Look, the Eastern Empire was saved by its capital's mobs - this is what Majorian could only dream of.

3) Geography: the Eastern Empire was divided in half by Constantinople, an impregnable fortress. This means that barbarians could not attack the rich provinces in Syria and Egypt, while the Persians could not threaten Greece and Thrace. In contrast, in the West, barbarians could walk all the way from Northern Gaul to Italy or even North Africa.

Northern China was also dominant in population and economy compared to the south.It’s where most of the population and taxes come from prior to the Song Dynasty.

 

[NedStark]

Northern China was also dominant in population and economy compared to the south.It’s where most of the population and taxes come from prior to the Song Dynasty.

Unlike Northern China AND the WRE, the ERE also had safer geography thanks to Constantinople's unique location that splits the Empire in 2 parts.

A better comparison is ERE before and after the Arab invasion.

 

[Avrorrange]

Unlike Northern China AND the WRE, the ERE also had safer geography thanks to Constantinople's unique location that splits the Empire in 2 parts.

A better comparison is ERE before and after the Arab invasion.

The WRE did have geography in the form of the Rhine, Danube and the Alps. Same deal with Northern China with the mountain ranges to the North, although by the time of the Western Jin Dynasty the barbarian tribes were already settled into China proper as foederati by Cao Cao and previous Han governments. Problem was that they couldn’t find the men to defend those borders. No matter how good your geography is, you still need to be able to find the men to defend the borders.

 

[Admiral_Zann]

Except that the East had massive advantages in economics, demographics and especially geography.

I give you economy but both in terms of population and geography the picture does look quite different.

2) Population: it had rich provinces with massive populations such as Egypt and Syria. Anatolia is also a good source of population. Thus, it had population advantage. The East also had significant advantages in terms of fighting manpower, the biggest example is the mobs of Constantinople who were capable of literally tearing Gainas' Gothic troops apart when Gainas was trying to pull a Stilicho/Arbogast and take power (compare this to Western Roman citizens whose biggest record was attacking Gothic soldiers' wives and children during Sack of Rome). Look, the Eastern Empire was saved by its capital's mobs - this is what Majorian could only dream of.

Going by modern estimates, the population difference between East and West was much smaller than might be thought. We are not talking about anything on the same scale as the North-South Divide in China here. A difference of between 2-4 million people is likely. Gaul and Italy retained large populations. The problem was that the Western government was unable to access that manpower after the 420s. That it had manpower comparable to the East is easily seen in the period of 388-394, as the West endures two defeats on the same scale as Adrianople and is still able to project its power when under competent leadership. The problem was that the West never had the long periods of stability under competent rulers that the East enjoyed during the era. By the 430s, the loss of Africa and weakening of the central government's ability to draw in taxes and soldiers had begun to really set the West on a course of no return.

Gainas is a bad example as he had only a few thousand soldiers against a city of several hundred thousand. Not to mention that city population does not translate to fighting strength. Rome had a population that could be just as volatile but was confronted by far larger enemy forces under Alaric and Gaiseric respectively. Not to mention that it did revolt against several emperors and helped throw them out.

3) Geography: the Eastern Empire was divided in half by Constantinople, an impregnable fortress. This means that barbarians could not attack the rich provinces in Syria and Egypt, while the Persians could not threaten Greece and Thrace. In contrast, in the West, barbarians could walk all the way from Northern Gaul to Italy or even North Africa.

Constantinople was far from impregnable. It fell more often to subterfuge than Rome fell to assault. You just need an enemy with the right amount of luck and the city is taken. As for borders, the ERE had a massive border with the Persians and luck that said Persians were focusing on their east during the late-4th century and the entirety of the 5th century. Whenever both fronts were under assault, ERE showed itself to be pretty fragile as could be seen with the last Roman-Sassanid War of 602-628. Not to mention that Anatolia and northern Syria are filled with Germanic, Isaurian and other foederati at the time. Their rebellions during the reign of Arcadius took decades to finally put down. Same way as with the West, the East just needs the right combination of bad luck and incompetence and their advantages evaporate.

 

[Admiral_Zann]

Lately I have been researching the Western Roman Empire and I have been making a mapgame of the usurpation of Magnus Maximus and I have asked myself the following question: What would have happened if the destinies of the West and East were reversed? that is, the Western Roman Empire manages to maintain its territories for a few more centuries while the East falls to the Goths and Vandals (and of course the Sassanids)

So what would be the effects of a surviving Western Roman Empire? And I don't mean a dying state retained in Italy and Africa, but maintaining its territories from Britannia to Germania and Illyria. Some may want to talk about the plausibility of this, but for the moment I would like to know the effects of this, certainly, peoples like the Franks and Visigoths no longer settle in Gaul and Spain, bringing various butterflies with them, what would happen to Germany? Magna in this scenario? Would independent kingdoms develop that would take advantage of the weakening of the West over time? Another thing that I wonder is the effects in the East, if some migrations are not diverted and settle in the East, how and where could they settle? Another question that arises to me is the Christianization of Eastern Europe, I think it would be a matter of time until missionaries arrive, but I see several butterflies here. Finally and in summary, how would the survival of the Eastern Roman Empire affect the events that took place throughout the 6th, 7th and 8th centuries?

As has been pointed out above, it is difficult to give precise effects without going into the reasons for collapse and survival. How and when the ERE collapses and what emerges from it would have huge effects on Western policy, same way the OTL successor states to the WRE determined Eastern foreign policy. However, there are a few general trends that would probably emerge:

1) the Church retains the advantage of a vast western European state structure to help facilitate its control. In OTL, the break-up of Europe into many small kingdoms meant that the Popes had to deal with a number of different actors, each bent to a degree on maintaining his own power vis-a-vis the Church. Here, while the Popes probably won't have as strong a position, they enjoy the support of the state aparatus and only have to deal with one important actor. The debate around the issue of the emperors intervening in church matters will continue just as well as it did in OTL, with something akin to the Doctrine of Two Swords developing slowly but surely.

2) a surviving Western Empire will definitely try to maintain its road and postal network. Both are essential for any realm to maintain order and control over its outlying regions. The result could be that western europe (outside Britain as the channel will remain a larger barrier for quiet a while) remains a more cohesive unit and may even cause the region to become the nucleus for a China-esque cycle of the Empire being restored after an eventual fall.

3) the West could retain the urban character of the Roman Empire for a lot longer, similar to the East until the later Arab Invasions.

4) Britain would remain a sore spot for the empire. The province is just too vulnerable to both foreign invasion and usurpation for anything else to be the case. It may still be abandoned and become the target of periodic military expeditions to preemptively defeat/subjugate any realm that would use Britain as a base to raid Gaul from. It would also probably become the preferred destination of exiles from the western empire, since it is far enough away to offer some security while close enough to take advantage of any change within the imperial court.

5) this one depends more on the way the Arab Migrations/Invasions play out. Even without Islam the pressures that affected the Arab tribes would cause some sort of migration from the penninsula in the 7th century. But if they don't move west, then North Africa could retain its fertile character for a while longer. The process of desertification was already ongoing but was vastly accelerated by the various wars and migrations unleashed after the Muslim conquest of the area. In this world, the process could be slower and ensure that Tunisia remains a breadbasket for longer.

6) this ATL WRE will inevitably shift from being centered on the Med to being centered on Gaul plus whatever parts of Germania they retain. Its economy is much more agrarian than the ERE's was and with things like the heavy plough allowing for soils further north to be exploited more will cause Gaul and Germania to grow in population. Gaul was already a core area of the WRE in the 4th and 5th century, providing large amounts of the realm's manpower, food and income, and this importance will only grow as time goes on. To some degree this would also depend on how the WRE deals with the Germanic kingdoms forming in Germania proper i.e. the Franks, Thuringians, Alemani etc. Expansion into the area like the Franks did in OTL is unlikely for quiet a while.

 

[CommieScum]

Constantinople was far from impregnable. It fell more often to subterfuge than Rome fell to assault. You just need an enemy with the right amount of luck and the city is taken.

Constantinople fell in civil wars often but never against a foreign army until the Latins

 

[Admiral_Zann]

Constantinople fell in civil wars often but never against a foreign army until the Latins

Doesn't change that it was vulnerable given the right circumstances. All you need is an ambitious man inside combining with an advancing army outside and the city is under threat. Roman propensity for civil wars at the most inopportune of times makes this even likelier. And especially if the Theodosian Walls are never built, which is possible given a PoD in the 380s.

 

[CommieScum]

Doesn't change that it was vulnerable given the right circumstances. All you need is an ambitious man inside combining with an advancing army outside and the city is under threat. Roman propensity for civil wars at the most inopportune of times makes this even likelier. And especially if the Theodosian Walls are never built, which is possible given a PoD in the 380s.

Whats your point? Doesnt change that this didnt happen for a millennia. Or that the walls dis have a rightful reputation after a point that proved enough of a deterrent in their own right. Ofcourse we wont be having the Theodosian Walls in this TL, the point is whether something like that is possible in the West. And more significant than the walls regarding Constantinople is ofcourse its control of the Bosphorous, which is what safeguards half the empire behind it. I am not sure where such a thing could be achieved in the West, perhaps Ravenna is best.

 

[NedStark]

Gainas is a bad example as he had only a few thousand soldiers against a city of several hundred thousand. Not to mention that city population does not translate to fighting strength. Rome had a population that could be just as volatile but was confronted by far larger enemy forces under Alaric and Gaiseric respectively. Not to mention that it did revolt against several emperors and helped throw them out.

I specifcally mentioned fighting manpower and the mobs of Constantinople was part of that fighting manpower - they historically contributed to the defense of Constantinople. They also had other regions relatively safe from barbarians (especially the Huns) that they never lost control.

It is often argued that the Eastern Roman population was still able to keep their martial traits by the V century, unlike Western Romans especially Roman Italians. Had Gainas succeeded, the East would have gone the way of the West. I mean, if you put Gainas and his troops inside say, Ravenna, and somehow removing the entire Ravenna garrison, they would have had a field day taking over the city. I mean, IOTL there was no Roman military presence in Constantinople, and the Gothic regiments were thoroughly wrecked by unarmed civilians.

I give you economy but both in terms of population and geography the picture does look quite different

Combined this with population, especially fighting population, the East was able to resist the barbarization of their own army - unlike the West.

As for borders, the ERE had a massive border with the Persians and luck that said Persians were focusing on their east during the late-4th century and the entirety of the 5th century. Whenever both fronts were under assault, ERE showed itself to be pretty fragile as could be seen with the last Roman-Sassanid War of 602-628

There was no single enemy that had the ability to attack both parts of the Eastern Roman Empire. Attila the Huns could ravage the Balkans, but he simply could not attack Egypt. In contrast, in the West, Attila could easily march straight to Rome in one single incursion. See the difference?

The Eastern Roman Empire also had much stronger fleets, so they could easily blocked any barbarian attempt to attack the Eastern parts.

 

[John I of Brazil]

I found an Interesting video that summarizes the reasons the roman population's loyalty to the empire might have weakened. While YouTube itself isn't a good source, this channel cited some interesting sources you guys might want to examine.