WI: Second Arab Siege of Constantinople (717-718) succeeds

[Bomster]

This seems to be one of the potentially most pivotal possible turning points in history. In 716, the Eastern Roman Empire was weakened by the Twenty Year’s Anarchy. The Umayyad Caliph, already overseeing an empire that stretched from Hispania to India, launched an invasion of Asia Minor, and by Summer 717 reached the outskirts of the City of World’s Desire, Constantinople. The Arabs assembled a massive land and naval force to besiege the city, and perhaps they could have done it. However, Roman naval superiority (thanks to Greek Fire), Bulgarian attacks on land, and disease, famine, and defections withered the formidable Arab army, forcing them to retreat by 718. The successful defense of Constantinople would revive the Eastern Roman Empire, and delay further Muslim advances into Christianizing Eastern Europe and the Balkans.

However, what if fortunes were reversed, and the Arabs successfully take Constantinople in the siege? Perhaps Kallinikos, inventor of Greek Fire, is captured by the Arabs decades prior, thus depriving the Romans of their most powerful weapon at sea, maybe even learning the secret of its formula themselves. Perhaps the Bulgarians refuse to help the Romans. I’m not an expert on this period of history, so perhaps there are potentially a multitude of PODs to consider, which I would also like to discuss.

What would have been the consequences of Constantinople’s fall in 718? The Roman Empire would almost surely collapse without its capital after suffering 20 years of discord, perhaps fragmenting into various duchies in Italy and Greece. Even if their hold on Constantinople and Asia Minor is temporary (Bulgaria could recapture the city once the Abbasids show up), the destruction of the Roman state would remove a massive barrier to the expansion of Islam into Europe. While the Arabs are unlikely to expand any further into the Balkans initially, the capture of Constantinople could massively impact the development of Kievan Rus, with the nascent Russian state adopting Islam instead of Orthodox Christianity as its religion. Christian Western Europe would be surrounded on all sides by Vikings and Muslims, perhaps hastening the formation of a HRE-like entity, and perhaps future Muslim advances through both sword and trade could result in the complete Islamization of the Mediterranean and Southern Europe. The possibilities are endless. What are your thoughts?

 

[Nivek]

his seems to be one of the potentially most pivotal possible turning points in history. In 716, the Eastern Roman Empire was weakened by the Twenty Year’s Anarchy. The Umayyad Caliph, already overseeing an empire that stretched from Hispania to India, launched an invasion of Asia Minor, and by Summer 717 reached the outskirts of the City of World’s Desire, Constantinople. The Arabs assembled a massive land and naval force to besiege the city, and perhaps they could have done it. However, Roman naval superiority (thanks to Greek Fire), Bulgarian attacks on land, and disease, famine, and defections withered the formidable Arab army, forcing them to retreat by 718. The successful defense of Constantinople would revive the Eastern Roman Empire, and delay further Muslim advances into Christianizing Eastern Europe and the Balkans.

The Siege started early since 713 but 717 was the main force, and greek fire is overrated, it was that the logistic end was exhausted , have the early siege being more successful, then the greek fire would have been a white noise

What are your thoughts?

Once the news are reached they conquered it, the main focus is expanding in the bosphorus/aegean, to secure it, meaning the little greek themes are on Muslim range and sight now...also sicily might fall into anarchy...another target too

 

[Bomster]

The Siege started early since 713 but 717 was the main force, and greek fire is overrated, it was that the logistic end was exhausted , have the early siege being more successful, then the greek fire would have been a white noise

How can the early siege be more successful?

 

[John Fredrick Parker]

So I had thoughts when we talked about the First Siege; I wonder how much of it is still relevant here:

If it’s possible to put aside the question of the capital’s relocation for this question -- what happens to Anatolia as a whole if Constantinople falls? Is it pretty much guaranteed to become overrun at that point?

If so -- and only here do we pick the capital question back up -- it doesn’t look like the Remnant Roman Empire has a lot of options remaining. Their best bet, as bad as it is, really is to relocate to Carthage and try to guard Sicily and the gates of the Western Mediterranean.

If Constantinople falls, then at minimum Thrace (and Adrianople) falls as well; as mentioned, Crimea is also likely lost; and I'd venture to guess that the Slavs likely take this opportunity to take Thessalanica. Also, Crete and Corinth are likely very vulnerable at this time as well (even if they lasted longer OTL).

So if I'm right about that much, then it seems the Empire is effectively split in two at this point -- in the east, the majority consolidates itself in Asia Minor; in the west, a new government in Carthage likely takes control of forces in Sicily, Italy, and the Western Mediterranean. If @Flavius Iulius Nepos is right about Anatolia becoming a tributary of the Caliphate, that gives them complete sway in the eastern mediterranean -- and even if the west holds out (more so than OTL even), Islam's longer term prospects for expanding their influence at Christianity's longer term expense is now pretty much limitless.

 

[Bomster]

So I had thoughts when we talked about the First Siege; I wonder how much of it is still relevant here:

I love these thoughts, though I have to clarify this is about the Second Siege, not the first. But a successful First Siege is also an interesting scenario because it would happen so early on in the Umayyad’s history. Of course this would probably butterfly Al-Andalus though. I feel the Second Siege is more plausible and interesting though.

 

[John Fredrick Parker]

I love these thoughts, though I have to clarify this is about the Second Siege, not the first. But a successful First Siege is also an interesting scenario because it would happen so early on in the Umayyad’s history. Of course this would probably butterfly Al-Andalus though. I feel the Second Siege is more plausible and interesting though.

Looking at a map of the Byzantines at time of the Second Siege, a lot of what I said then seems to hold:

Maps on the Web: Photo

Maps on the web, maps from the web, charts and infographics.

mapsontheweb.zoom-maps.com

Outside of Anatolia, the empire is pretty stretched for territory at this time; and a lot of the remaining territory in the east (eg Thessalonica) would be very susceptible to the Ummayads if the capital fell.

 

[Bomster]

Looking at a map of the Byzantines at time of the Second Siege, a lot of what I said then seems to hold:

Maps on the Web: Photo

Maps on the web, maps from the web, charts and infographics.

mapsontheweb.zoom-maps.com

Outside of Anatolia, the empire is pretty stretched for territory at this time; and a lot of the remaining territory in the east (eg Thessalonica) would be very susceptible to the Ummayads if the capital fell.

Yeah the Byzantines are dead. And even if they manage to survive, like if a successor state in Greece or Italy retakes the city like Nicaea recapturing the city from the Latins IOTL, they will be severely weakened and most likely reduced to a vassal of the Bulgarians. Taking out the Byzantine Empire will remove perhaps the biggest obstacle to further expansion of Islam into Europe. Perhaps Italy is next?

 

[Silver01]

well the first bulgarian empire likely takes Nesebar and likely sofia in fact it would not be suprising if bulgaria does krum conquest earlier and they migth even get adrinople before the arabs as they have to secure other things still i suspect the caliphate would take over anatolia and thrace and costal cities like thasselonica

 

[Bomster]

well the first bulgarian empire likely takes Nesebar and likely sofia in fact it would not be suprising if bulgaria does krum conquest earlier and they migth even get adrinople before the arabs as they have to secure other things still i suspect the caliphate would take over anatolia and thrace and costal cities like thasselonica

The Bulgarians are probably the biggest obstacle in the Balkans to spreading Islam/Umayyad rule, after Byzantium. I can see Anatolia, Thrace, and Most of modern Greece under Caliphal control or influence, while the Bulgarians lord over the Balkans. What kind of interactions would we see between the Caliph and the Khan? Will Islam spread into Bulgaria?

 

[Silver01]

The Bulgarians are probably the biggest obstacle in the Balkans to spreading Islam/Umayyad rule, after Byzantium. I can see Anatolia, Thrace, and Most of modern Greece under Caliphal control or influence, while the Bulgarians lord over the Balkans. What kind of interactions would we see between the Caliph and the Khan? Will Islam spread into Bulgaria?

not for a long while the bulgarians killed priest and were rejected chirstianity on the basis that having greek priest and having the religion migth be a gate way for byzantine conquest, at this early age of islam to convert not only meant become a mulsim but also submission to the caliphate if the bulgarians were so paranoid of migth there not going to accept will

 

[Bomster]

not for a long while the bulgarians killed priest and were rejected chirstianity on the basis that having greek priest and having the religion migth be a gate way for byzantine conquest, at this early age of islam to convert not only meant become a mulsim but also submission to the caliphate if the bulgarians were so paranoid of migth there not going to accept will

I wonder if this ironically makes it easier for the Bulgarians to convert to Christianity out of opposition to the Muslim Caliphate. Without the Byzantines this probably means they align themselves with Western Europe more.

 

[Silver01]

I wonder if this ironically makes it easier for the Bulgarians to convert to Christianity out of opposition to the Muslim Caliphate. Without the Byzantines this probably means they align themselves with Western Europe more.

i dont think that would be likely unless the franks still become powerfull and conquer the avars, because in their views chirstianity would be viewed as weak given how it was conquered the only way i see this if enough chirstians flee to bulgaria and the khan marries byzantine royals then he migth at least try to say he treats roman subjects better than the caliphate

 

[Bomster]

i dont think that would be likely unless the franks still become powerfull and conquer the avars, because in their views chirstianity would be viewed as weak given how it was conquered the only way i see this if enough chirstians flee to bulgaria and the khan marries byzantine royals then he migth at least try to say he treats roman subjects better than the caliphate

Perhaps once the Umayyads inevitably find themselves in turmoil (Berbers, Abbasids), the Bulgarians could make a play for Constantinople, and proclaim themselves the inheritors of the Roman Empire? Then again taking the city back from the Arabs might be difficult.

 

[Nivek]

Perhaps once the Umayyads inevitably find themselves in turmoil (Berbers, Abbasids), the Bulgarians could make a play for Constantinople, and proclaim themselves the inheritors of the Roman Empire? Then again taking the city back from the Arabs might be difficult.

I think the Bulgarians might expand north and west first, as there ripping targets in the Balkans and lack of a navy make the Aegean and Constantinople very difficult.

The Bulgarians are probably the biggest obstacle in the Balkans to spreading Islam/Umayyad rule, after Byzantium. I can see Anatolia, Thrace, and Most of modern Greece under Caliphal control or influence, while the Bulgarians lord over the Balkans. What kind of interactions would we see between the Caliph and the Khan? Will Islam spread into Bulgaria?

Unironically depending they could if they take advantage to get the Muslim trade routes and a way to power if the ummayds/abbasid power falter? The fate of the ummayd is something too.

 

[Bomster]

I think the Bulgarians might expand north and west first, as there ripping targets in the Balkans and lack of a navy make the Aegean and Constantinople very difficult.


Unironically depending they could if they take advantage to get the Muslim trade routes and a way to power if the ummayds/abbasid power falter? The fate of the ummayd is something too.

Would the Umayyads focus on Italy or the Balkans next?

 

[Hastings]

So, Byzantines are obviously going to be in very bad shape. But Umayyads still have a lot of work to do. Most of Anatolia is still free. Chipping apart I think will take awhile to complete. It will take a series of campaigns. Assuming something doesn’t blow up elsewhere, they probably largely win that eventually, but will take awhile. I could easily see a Trebizond analogue or for a more contemporary example, like the Persian states on south shore of Caspian Sea, surviving. Umayyads aren’t making Constantinople their capital, their power base is very much Syria.

Sicily, Sardinia, Corsica, lot of coastal footholds in Italy, Adriatic coast form nice base for someone claiming to be Emperor. Umayyads will have a lot to mop up in Aegean, so I expect this state to get a breather. I think these breakaways may be surprisingly robust, they can be locally focused in a way an empire cannot, just like the Byzantine successors >1204 held up pretty well.

Other thing is Bulgarians. Umayyads realistically aren’t going to be knocking them out anytime soon, and they are Byzantine allies. I suspect they’ll support a puppet, then eventually just directly absorb. I expect Bulgaria will reach its mid-800s frontiers in Balkans much sooner. Sofia, Plovdiv, more of Northern Thrace, easy pickups. This could be interesting, Bulgars are still very much Turks with Slav ‘allies’ at this point.

There is going to be a bit of a refugee crisis going on. Greek Orthodox were *much* less fine with Muslim rule than Miaphysites and tended to emigrate in bulk, most dramatically in Palestine, and this often continued *well* after initial conquest. Byzantine Italy will be getting literally hundreds of thousands of refugees from the Aegean and coastal Anatolia in next few decades. Bulgaria’s territories south of Balkan Mountains will get a lot from Thrace/Constantinople (which has way too large a population now it is no longer an imperial center). Will also be shuffling internally to holdouts in Anatolia. I think this gets overlooked in discussions.

This will be interesting for Bulgars. Do they assimilate with Slavs still or does gaining a large urban Greek population much earlier plus larping as true successors to Rome mean their elite Greekify? Also means Byzantine Italy may do well if good management. Lombards have fairly good leaders for much of 700s, but frankly were never a real muscular realm, basically only gains they made during this period were as result of Iconoclast mess. I could see starting to push out in places like Apulia and settling Greek urban populations…

Umayyads will still fall sooner or later. There was a long-running tendency toward Arab favoritism in the dynasty, big revolts were common. This doesn’t really fix that. More prestige, but I would also tend to expect Anatolia to be like North Africa or Persia, stuffed full of cranky people either non-Muslim or heretic. Given how relatively brief Umayyad rule is, I could even see a bit of a reversion to Greek rule for a time. Do we then get Abbasids or similar or earlier breakdown into smaller states like post-Abbasids?

I can see arguments either way long-term for Bulgaria converting to Christianity earlier versus going Islam. Rus are much more likely to go Muslim.

 

[Bomster]

So, Byzantines are obviously going to be in very bad shape. But Umayyads still have a lot of work to do. Most of Anatolia is still free. Chipping apart I think will take awhile to complete. It will take a series of campaigns. Assuming something doesn’t blow up elsewhere, they probably largely win that eventually, but will take awhile. I could easily see a Trebizond analogue or for a more contemporary example, like the Persian states on south shore of Caspian Sea, surviving. Umayyads aren’t making Constantinople their capital, their power base is very much Syria.

Sicily, Sardinia, Corsica, lot of coastal footholds in Italy, Adriatic coast form nice base for someone claiming to be Emperor. Umayyads will have a lot to mop up in Aegean, so I expect this state to get a breather. I think these breakaways may be surprisingly robust, they can be locally focused in a way an empire cannot, just like the Byzantine successors >1204 held up pretty well.

Other thing is Bulgarians. Umayyads realistically aren’t going to be knocking them out anytime soon, and they are Byzantine allies. I suspect they’ll support a puppet, then eventually just directly absorb. I expect Bulgaria will reach its mid-800s frontiers in Balkans much sooner. Sofia, Plovdiv, more of Northern Thrace, easy pickups. This could be interesting, Bulgars are still very much Turks with Slav ‘allies’ at this point.

There is going to be a bit of a refugee crisis going on. Greek Orthodox were *much* less fine with Muslim rule than Miaphysites and tended to emigrate in bulk, most dramatically in Palestine, and this often continued *well* after initial conquest. Byzantine Italy will be getting literally hundreds of thousands of refugees from the Aegean and coastal Anatolia in next few decades. Bulgaria’s territories south of Balkan Mountains will get a lot from Thrace/Constantinople (which has way too large a population now it is no longer an imperial center). Will also be shuffling internally to holdouts in Anatolia. I think this gets overlooked in discussions.

This will be interesting for Bulgars. Do they assimilate with Slavs still or does gaining a large urban Greek population much earlier plus larping as true successors to Rome mean their elite Greekify? Also means Byzantine Italy may do well if good management. Lombards have fairly good leaders for much of 700s, but frankly were never a real muscular realm, basically only gains they made during this period were as result of Iconoclast mess. I could see starting to push out in places like Apulia and settling Greek urban populations…

Umayyads will still fall sooner or later. There was a long-running tendency toward Arab favoritism in the dynasty, big revolts were common. This doesn’t really fix that. More prestige, but I would also tend to expect Anatolia to be like North Africa or Persia, stuffed full of cranky people either non-Muslim or heretic. Given how relatively brief Umayyad rule is, I could even see a bit of a reversion to Greek rule for a time. Do we then get Abbasids or similar or earlier breakdown into smaller states like post-Abbasids?

I can see arguments either way long-term for Bulgaria converting to Christianity earlier versus going Islam. Rus are much more likely to go Muslim.

Long term the islamicization of the Eastern Slavs is probably the biggest consequence of this scenario. That is, if the Arabs manage to hold Constantinople at all for an extended period of time.

 

[Zygmunt Stary]

well the first bulgarian empire likely takes Nesebar and likely sofia in fact it would not be suprising if bulgaria does krum conquest earlier and they migth even get adrinople before the arabs as they have to secure other things still i suspect the caliphate would take over anatolia and thrace and costal cities like thasselonica

I think Balkans will be taken over by 1st Bulgarian empire, when Anatolia by Arabs.

 

[Zygmunt Stary]

Long term the islamicization of the Eastern Slavs is probably the biggest consequence of this scenario. That is, if the Arabs manage to hold Constantinople at all for an extended period of time.

Not tenable, because pig is too important as food source and with POD that far there might not even be Rus' whose rulers depended on trade with Constantinople, Bulgarians strenghtened by owning Balkans would probably absorb at least the eastern part of Avar khaganate as per OTL and subjugate OTL's Ukraine by themselves.

 

[Nivek]

Not tenable, because pig is too important as food source and with POD that far there might not even be Rus' whose rulers depended on trade with Constantinople, Bulgarians strenghtened by owning Balkans would probably absorb at least the eastern part of Avar khaganate as per OTL and subjugate OTL's Ukraine by themselves.

there also other migrations but the balkans might become a battleground 8 centuries earlier between Muslims and non Muslims too