WI Succesful Caliphate invasion of Constantinople?

[Maburo]

What if the Arabs succesfully took Constaninople during the first siege in 674-678? Would they be able to take the entire Roman Empire as they did the Persian? Or would the Empire be able to succeed and relocate its capital? What would this fall mean for the future of the Orthodox Church? How would Western Europe be likely to react to this development? How would this success effect future expansion and development of the Caliphate?

Any and all thoughts welcome

 

[Parmenion]

The empire had exclaves as far away as north Italy, the Belarics, and Crimea. They won't get all of it, but most of what's left will get swept up by opportunists.

 

[Maburo]

The empire had exclaves as far away as north Italy, the Belarics, and Crimea. They won't get all of it, but most of what's left will get swept up by opportunists.

But if they take Constantinople, what would happen to all these holdings in Italy, the Balearics, and Crimea? Does the Roman Empire just move capital and continue governing? Does it collapse with generals and local governors carving out breakaway kingdoms of their own?

 

[Ed of the Pueblos Libres]

In some threads the possibility or proposals of certain Roman emperors to move the capital to (at least) Carthage & Syracuse, have been discussed - both during the Heraclian dynasty I think.
The army wasn't very fond of the idea of moving the capital to Syracuse so they killed that guy that proposed this option.

 

[Nivek]

What if the Arabs succesfully took Constaninople during the first siege in 674-678? Would they be able to take the entire Roman Empire as they did the Persian? Or would the Empire be able to succeed and relocate its capital? What would this fall mean for the future of the Orthodox Church? How would Western Europe be likely to react to this development? How would this success effect future expansion and development of the Caliphate?

Any and all thoughts welcome

If the first siege is won, they will be in full chaos,at the same time the caliphate was sweeping north Africa, ittl Sicily will be tempting target too, so that will be the end the ere

 

[Madhukar_Shah]

An important point I’d say would be who is actually commanding the Arab army and who Anatolia and Constantinople itself is assigned to. Mu’awiya is just about to nominate his son as heir to the caliphate and this is definitely going to influence the succession and eventual second Fitna- possibly making the fitna a lot worse as Byzantine territories would provide another army/power base for people to bring into play.

I can’t imagine the new administration just settling into Constantinople- how could a governor live amongst imperial palaces and not claim the imperial mantle himself? Islam is still new enough of a cultural force that I wouldn’t be surprised if there is a strong hellenising tendency in arabs governing Rome. Mu’awiyas Syrian administration was probably all in Greek, and the sole epigraphic trace of his administration is a Greek inscription, which bears a cross before his name- an attempt at Christianising/hellenising Islam might not be off the cards for him. A translatio imperii- whereby instead of being a Greco-Latin empire, Rome would now be Greco-Arab, with military governorships of course reserved for Arab leaders.

What are the chances of Mu’awiya himself moving into Constantinople and seizing personal control? It seems to fit in with his personal ambition but would seriously damage his Arab credibility if he adopted the trappings of a Byzantine emperor, even one that’s doctrinally Muslim.

Imagine an alt Karbala between Muslim Byzantine Emperor Yazid and the more arab forces of Husayn.

 

[Nivek]

But if they take Constantinople, what would happen to all these holdings in Italy, the Balearics, and Crimea? Does the Roman Empire just move capital and continue governing? Does it collapse with generals and local governors carving out breakaway kingdoms of their own?

They're unable to hold Crimea and Balearics without the Greek shipworks so those are gone, Italy the Lombards and local goths will take advantage to revolt and overthrow them.

Which other capitol? Carthage will feel soon just leaving Sicily

 

[John Fredrick Parker]

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.

 

[Flavius Iulius Nepos]

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.

Pretty much guaranteed in this scenario that you would have multiple claimants to the purple: no way the top guy in Anatolia is able to control Africa or viceversa (not with Constantinople gone and the eastern Med pretty much an Arab lake).

My guess for what happens next:

1) Crimea is gone, not enough resources left to prop it up and probably not even worth it;

2) Anatolia would be a tough opponent for the Arabs to deal with, as it was and still would be in this scenario the actual heart of the ERE. Depending on whether the locals are smart enough to gather around one single leader, I could see it surviving, albeit as a tributary of the Caliphate. if not it just gets conquered piecemeal;

3) Balkan possessions are most likely lost to the Slavs/Bulgars. I could see Thessalonika surviving for a while depending on whether they get some support from any of the other roman splinter states;

4) Africa, probably the richest possession left in the hands of the empire. With proper support from the rest of the western holdings and assuming the aftermath of the conquest of Constantinople keeps the Arabs busy for a while, I can see the Romans building a functional state here.

5) Sicily was pretty much competing with Africa in terms of what they could provide to the imperial coffers. Not facing any threat from the Lombards and unlikely to face major attacks from the Arabs, as long as Africa stands.

6) Italy, is in a worse situation compared to Africa and Sicily but also not yet at a point where the Roman cause here was hopeless. Imperial holdings here are still sizable, plenty of cities and harbours still in Imperial hands and despite receiving very little help from the ERE IOTL, managed to survive for another century (four in the south). So I say there is a good chance a decent emperor can do something here.

Now the important question is whether one of the Exarchs (or the guy in charge of Sicily) can establish his authority over the other two. A combined West is a more impressive foe than three bickering statelets fighting each other for the scraps.

 

[Nivek]

) Africa, probably the richest possession left in the hands of the empire. With proper support from the rest of the western holdings and assuming the aftermath of the conquest of Constantinople keeps the Arabs busy for a while, I can see the Romans building a functional state here

Muslim are already at the gates of Tunisia, that's gone

 

[Flavius Iulius Nepos]

Muslim are already at the gates of Tunisia, that's gone

Romans still control it and IOTL they controlled it for 2 more decades, only losing it in the anarchy following Justinian's death. I say what the Romans do can still have an impact on what's going on in that area.

 

[Nivek]

How would this success effect future expansion and development of the Caliphate?

Back into this ,the Greco-Roman cultural wealth of Anatolia and Constantinople would add a new cultural node to the caliphate,I think a house of wisdom in Constantinople would happen very quickly

 

[John Fredrick Parker]

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.

 

[Nivek]

Cornish

Corfu?

 

[Nivek]

Cornith -- damn autocorrect!

I see ,I knew was a misspelling but wondering which one, thanks

 

[raharris1973]

Cornish

?

If @Flavius Iulius Nepos is right about Anatolia becoming a tributary of the Caliphate

I wonder what part or parts of Anatolia would remain Roman autonomous, and what part would be part of the Caliphate to provide territorial continuity to Constantinople & Thrace.

 

[Vulgarian]

Good chance you get a much more westernised Islam in the long run - this was still very early days.

Or possibly a big split in Islam emerges between a romanised Islam and a more Persian one.

 

[Nivek]

Good chance you get a much more westernised Islam in the long run - this was still very early days.

Or possibly a big split in Islam emerges between a romanised Islam and a more Persian one.

It also depends what happened to Abbas

 

[wakobear]

2) Anatolia would be a tough opponent for the Arabs to deal with, as it was and still would be in this scenario the actual heart of the ERE. Depending on whether the locals are smart enough to gather around one single leader, I could see it surviving, albeit as a tributary of the Caliphate. if not it just gets conquered piecemeal;

With Constantinople, and the OTL Umayyad bases in Cyzicus, Lycia, Smyrna, Rhodes and Crete, they would gain unchallenged control over the Aegean and eastern Mediterranean as a whole.
Which would allow them to take the entirety of the Anatolian coast, South, North and West. Providing beachheads from which inner Anatolia can be assailed.
Of which western Anatolia is the richest and most important, which would be quite vulnerable to forces coming from Smyrna, Antalya and Marmara. Once the west falls, the rest of Anatolia is sure to follow.

3) Balkan possessions are most likely lost to the Slavs/Bulgars. I could see Thessalonika surviving for a while depending on whether they get some support from any of the other roman splinter states;

The naval monopoly on the Aegean makes Thessalonika isolated, since the South Slavs controlled all non coastal Southern Balkans.
Meaning it can fall quite easily as well as Athens and other Coastal Balkan cities, providing direct Caliphal contact with the slavs and later Bulgars. With Constantinople gone, so to are incentives to convert to Christianity, so they would likely gradually convert to Islam, especially if Caliphal policy encourages this.

4) Africa, probably the richest possession left in the hands of the empire. With proper support from the rest of the western holdings and assuming the aftermath of the conquest of Constantinople keeps the Arabs busy for a while, I can see the Romans building a functional state here

With Constantinople taken, much more attention would be placed on the west. Especially if it becomes centre of new Byzantine resistance.
Unlike OTL, where the Maghreb was more of an afterthought.

Most importantly, the naval expansion caused by capturing Anatolian and Balkan shipyards, and the total naval monopoly on the eastern Mediterranean would allow the navy to take a major role in the western conquests, unlike OTL.

So a few years after taking Constantinople, the full might of the Caliphal navy, as well as a much larger invasion force than OTL, would probably be able to take Africa with ease.

The Roman position was greatly weakened after Sufetula. The Byzantine refugees would probably find it difficult to exert much power outside the environs of Carthage.
And even with naval support from Sicily, they wouldn't be able to compete with the full might of the expanded Caliphal navy. Allowing for a Land and Sea seige of Carthage.
Perhaps due to greater Muslim confidence in their navy, choosing Carthage as their capital, instead of Qayrawan.

With Carthage, the rest of the Maghreb would eventually follow. The navy speeding up the conquest, as well as the greater amount of focus and resources given to the west.

5) Sicily was pretty much competing with Africa in terms of what they could provide to the imperial coffers. Not facing any threat from the Lombards and unlikely to face major attacks from the Arabs, as long as Africa stands.

Finally with Africa and the Maghrebi coast, all that remains is Sicily.
This would be the last bastion of the Byzantines, who would put up a dogged defence, using its mountainous topography to make conquest incredibly difficult.
But the Caliphate would have naval superiority, and Sicily would have 0 outside support. Palermo and Syracuse would fall fairly quickly. But the push into the interior would be slow.
Perhaps taking a decade...

6) Italy, is in a worse situation compared to Africa and Sicily but also not yet at a point where the Roman cause here was hopeless. Imperial holdings here are still sizable, plenty of cities and harbours still in Imperial hands and despite receiving very little help from the ERE IOTL, managed to survive for another century (four in the south). So I say there is a good chance a decent emperor can do something here

With Sicily, Caliphal naval dominance would be established throughout the entirety of the Mediterranean. Leaving Italy only a matter of time, though rugged terrain would slow down efforts.
The Balkan navies establishing dominance over the Adriatic, influencing the Po Valley.
While Sicilian/Maghrebi navies take Naples. Soon taking Rome itself. All 5 patriarchates would now be in Muslim hands, crippling all Christianity.



Later, complete naval control over the Mediterranean, as well as much more manpower and resources would make the Iberian campaign quicker and more successful.

A quicker Iberian Campaign, would allow a sooner invasion of Frankia, before the Peppinids can start strengthening it.

Massive Mediterranean navy would give complete unchallenged control over Septimania and Provence. And allow naval invasions up the Rhone river.
An Iberian Atlantic navy, brought about by the greater naval focus of the Caliphate, would allow a conquest of western Frankish coast and up the Garonne, Loire and potentially Siene...
(As well as raids on British Isles)
While Muslim Po Valley would also be able to assist in invasions of southern and eastern Frankia.

With the 100k troops that took part in the 717 siege, being able to be used elsewhere. Ending Frankia.
(Though a much better use of them would be invading the unimaginably wealthy northern India, still a mess since Harsha's death in 647).


The only independent Christian statelets remaining would those in Ireland, Britain and somewhat Axum.
(Though adventurers from Asturias and western Frankia could do viking style raids on the British isles, especially since they have much greater manpower)

 

[wakobear]

An important point I’d say would be who is actually commanding the Arab army and who Anatolia and Constantinople itself is assigned to. Mu’awiya is just about to nominate his son as heir to the caliphate and this is definitely going to influence the succession and eventual second Fitna- possibly making the fitna a lot worse as Byzantine territories would provide another army/power base for people to bring into play.

I can’t imagine the new administration just settling into Constantinople- how could a governor live amongst imperial palaces and not claim the imperial mantle himself? Islam is still new enough of a cultural force that I wouldn’t be surprised if there is a strong hellenising tendency in arabs governing Rome. Mu’awiyas Syrian administration was probably all in Greek, and the sole epigraphic trace of his administration is a Greek inscription, which bears a cross before his name- an attempt at Christianising/hellenising Islam might not be off the cards for him. A translatio imperii- whereby instead of being a Greco-Latin empire, Rome would now be Greco-Arab, with military governorships of course reserved for Arab leaders.

What are the chances of Mu’awiya himself moving into Constantinople and seizing personal control? It seems to fit in with his personal ambition but would seriously damage his Arab credibility if he adopted the trappings of a Byzantine emperor, even one that’s doctrinally Muslim.

Imagine an alt Karbala between Muslim Byzantine Emperor Yazid and the more arab forces of Husayn.

As for the 2nd fitnah:​

Abdullah ibn Zubayr and Abdullah ibn Abbas (Husayn's father's cousin) as well as other significant companions took part in the siege of Constantinople OTL, campaigning under the (honorary?) command of Yazid.
With Yazid's victory, his fame, glory and perceived ability as a leader would be launched into the stratosphere.
Along with that, ibn Zubayr, Ibn Abbas, ibn Umar etc would have massive influence in Constantinople, probably appointed as governors of Thrace, Bithynia or Smyrna by Muawiyah.
And more generally, immense wealth would flow into the Caliphate, making the people less likely to revolt.


I don't see Muawiyah moving the capital to Constantinople. He was in late 70s/early 80s.
And Syria was where the entire Umayyad powerbase was, even before Islam. And the Syrian Jund/army was one of the largest in the Caliphate.
Moving to Constantinople alienates your entire powerbase, and isolates you. While anti-Umayyad Iraq and the entire east of the Caliphate would be completely out of your control, Rebelling almost immediately...





Ibn Zubayr and Husayn would still reject the notion of a non Sahabi being Caliph over those who lived with the prophet.
With Husayn believing similar.
So if Yazid deals with Husayn's contention in the most unfathomably stupid way possible, as OTL, the outrage would still be massive.

But the Umayyads are in a much stronger position, with much more prestige, wealth and manpower. And not having to worry about Byzantine attacks from the north, thereby not requiring the OTL tribute payments.
So the Umayyads would come back into power sooner.

But the shift to Constantinople would have to be a gradual process, only possible once most of inner Anatolia is conquered.








Unless ibn Zubayr chooses Constantinople. Instead of isolated Makkah.
Since he would likely have massive respect among the conquering army of Constantinople, due to his status as a senior companion. As well as an esteemed warrior, being part of Yarmuk, conquest of Egypt and being the reason for victory at Sufetula.
Probably having more respect than Yazid himself.....
Especially if ibn Abbas, ibn Umar and other companions of the army of Constantinople join him.

Taking the city, when Yazid is in Syria, to tend to his dying father, and ensure the loyalty of the Marwanids and Syrian army.

This would give him control over the Aegean fleet, and a near impregnable capital.....
Initially, just protesting Yazid's ascension to the Caliphate.

But then Karbala would happen, so that ibn Zubayr would no longer be merely rejecting Yazid., but aiming for the elimination of the Umayyads.

Until Yazid's, death, not much fighting between the two would occur.
With yazid busy keeping Iraq and Madinah/Hejaz as well as Khawarij under control. The sheer distance of Ibn Zubayr would make him difficult to deal with.

Meanwhile, ibn Zubayr would be improving his navy, and perhaps improving his manpower base through recruitment of Slavs and Anatolians

After Yazid's death in 683, the whole Caliphate is thrown into anarchy.
He would be able to use Constantinople's far more strategic position to create a much stronger Zubayrid Caliphate than OTL.

The Zubayrid navy, would quickly take Cyprus, Egypt and Levantine coast.
Using the coast for much more influence in the interior, particularly fairly nearby Damascus via Acre, Tyre and Beirut.

Ideally preventing the Marwanids from even establishing a presence in Syria which was Sufyanid, the Marwanids were mostly in Hejaz, until they got kicked out OTL by ibn Zubayr.

Even if that's not possible, Marj Rahit would end in a Zubayrid victory, with Marwan being slain.
This would result in Qays being more dominant than Yaman.




Iraq would be more difficult to control, due to the sheer distance from Constantinople, and the Anatolian interior not being conquered. Although Makkah was quite far too....
(Makkah is 1250km Constantinople is 1700km)

If ibn Zubayr sent ibn Abbas to Iraq instead of Musab, he should be able to take control over the Shi'ite sentiments in Iraq, since he was the cousin of the prophet, and one of the most senior scholars of the companions.
Instead of Mukhtar ath-Thaqafi, who was claiming for Muhammad alHanafiyyah, despite the latter being against his claim, and not being a companion or son of Fatima

After Marj Rahit, Zubayrids would also have control over the Syrian army, largest in the Caliphate. Giving much greater manpower than OTL, making Mukhtar and the Khawarij much easier to defeat.
(Though Mukhtar might not even rebel in wake of Marj Rahit, seeing all the cards against him....)


Probably ending the fitnah by mid 685. Only a year and a half after Yazid's death, instead of 10...
Meaning, the Caliphate is in civil war for much shorter, making its effects much less potent.

Allowing a quicker return to expansion, as detailed in my previous post.



Ibn Zubayr would probably keep Constaninople as the capital, as it's where his powerbase is strongest.
With Kufa. (Or ideally more strategic Baghdad) as second capital of the east.

Sidepoints​

Ibn Zubayr could speak Persian, Ethiopian, Greek, and Hebrew. Speaking to his slaves in their native languages. As mentioned https://openresearch-repository.anu...01_Ilhan_Abd_Allah_Ibn_Al-Zubayr_and_2018.pdf

Since he personally speaks Greek and is in Constaninople, this could perhaps result direct Hellenification of the empire?
But overall, once Greeks begin to convert in the late 8th, 9th and 10th centuries, they would probably have a bigger cultural impact on Islam than the Persians.



But since the Muslims now have control over the main mint of the Byzantines, they no longer have to copy Byzantine motifs, and can carry out AbdalMalik style coinage reform and Arabisation in general.
Whether they would actually do that or not is uncertain.

Beyond that, Haiga Sophia would become a mosque, greatly influencing Islamic architecture as a whole...



With Umayyads and Mukhtar defeated, sunnism and Shi'ism probably wouldn't split.


Overall the butterflies this TL would cause would be utterly immense....