Just how big *could* the Early Caliphates have gotten

[water123]

There is no denying that the explosive growth of the early Muslim Caliphates arguably was the greatest act of expansion of a power since Alexander the Great's Empire. At the "high water mark" of the Caliphate, the empire straddled from Aquitaine all the way to India.

My question is, in light of this, just how big could the early Islamic Caliphates have gotten, especially if, say, there was not as many civil wars in the late Umayyad period? What important cities or other landmarks could have been taken by the Caliphates

-The total conquest of Spain is a pretty simple thing for the Caliphate to do once Andalusia was nailed down. The Basque Highlands and the Alps would probably remain Christian for along time, if just because of remoteness.

-Constantinople was commanded by Muhammad himself to be conquered, and was besieged many times. No Greek Fire and a bit more administrative stewardship to avoid a civil war could have easily lead to Constantinople have fallen.

-The Frankish Empire was really just kind of a group of Barbarians until the defeats of the Muslims by Charles Martel and Charlemagne. Plus, parts of southern Toulouse were occupied at one point. A series of Frankish defeats, especially if some ambitious nobles converted to Islam to advance their position, could have left the Caliphate on the offensive in Paris. Just how far the Islamic armies could have marched into France and Germany is really dependent on how resistant is the population is.

-In the end, I think that England might be out of the Caliphate's grasp. The Caliphate's navy was busy keeping up trade, and was better in the Mediterranean. A rather forward thinking minor son of a rather important member of the Caliphate's administration in Europe could take over a bit of land in Ireland or Britain, but it really isn't in the Caliphate's reach to conquer England.

-If the Caliphate can conquer Gaul/Frankia, Italy is doomed. It already was having problems IOTL.

-Pagan Europe is pretty much a no go outside of independent proselytization.


As for non-European targets

-Northern India is a possibility. It would depend on how structured the Caliphate is at the time, the amount of momentum that had been built up, the opinion of the Caliphate in India, and how united India is. Like England, however, it is more likely to be taken by independent Muslim rulers than by the Caliphate proper.

-Abyssinia and Nubia really only held out because of geography. If the Caliphate uses European shock troops to do it's dirty work, its not a matter of if but when.

-Mali is a lot like the Norse lands. It is going to be pretty easily converted to Islam if just because of how divided African Spirituality is and how scary the Caliphate would be after conquering a lot of Europe, Africa, and India.

-Western Coastal Africa is possible, but... why? It is impoverished and rather useless.

-The Steppes would be pretty hard to take over. Again, easier done by an independent Muslim power, but by the Caliphate proper it is pretty difficult.

-Tibet is another Independent Muslim target.

-China is a no no.



And on another note, what do you think a Muslim Europe would be like? Would the concepts of Englishman, Frenchman, German, Italian, etc develop similarly, or would there be new nationalities that evolved similar to the concept of the Andalusian?

 

[DominusNovus]

I think you're being a little optimistic in your suggestions in Asia. Also Ethiopia held out for reasons other than geography. Just as Muhammad told his followers to take Constantinople, he also told them to leave Ethiopia alone.

 

[Emperor-of-New-Zealand]

I think China, or at least parts of China, converting is more likely than Tibet, which had the safety of the Himalayas and practically independent monasteries scattered throughout the mountains. The Steppes eventually did become Muslim, so I don't know why your ATL would exclude them?

The greatest extent I can really imagine is an Islamic Roman Empire stretching from Persia to Spain. I don't believe it could hold together for very long, though, and the early Muslims would need to become amenable to Christianity pretty quickly.

 

[water123]

I think you're being a little optimistic in your suggestions in Asia. Also Ethiopia held out for reasons other than geography. Just as Muhammad told his followers to take Constantinople, he also told them to leave Ethiopia alone.

Huh, did not know that. Nubia is still probably in danger, but in that case Ethiopia might end up being "encouraged" to convert.

I think China, or at least parts of China, converting is more likely than Tibet, which had the safety of the Himalayas and practically independent monasteries scattered throughout the mountains. The Steppes eventually did become Muslim, so I don't know why your ATL would exclude them?

The greatest extent I can really imagine is an Islamic Roman Empire stretching from Persia to Spain. I don't believe it could hold together for very long, though, and the early Muslims would need to become amenable to Christianity pretty quickly.

I meant that the Steppes coupd not be conquered by the Caliphate. They would probably independently convert. However this alone seems to make conversion of large parts of China to islam unlikely because of all of the raiders being Islamic. It would make OTLs silk road look pitiful in comparasin though.

The only way Tibet would convert is if a Tibetan Muslim took control and formed a "new tibetan empire." i know that a lot of monasteries are pretty open to new ideas, though Islamic Monasticism seems to be tough to allow for.

I was more seeing the Caliphate as an entity that would sweep over large portions and then collapse due to overextension except in a Berber and Arabo-Leviantine "core."

The thing about Islam is that it is so similar to Christianity (in fact, many churches otl to this day consider Islam a heresy instead of an outright seperate religion) that it could become the Christian orthodoxy, similar to the Iconoclasm in the Byzantine Empire. Even better if they can get the Pope to convert, which is a real possibility. Plus tze system that allowed for North Africa to convert rather rapidly would happen in Europe: A wealthy Islamic nobility built off of a tax on islamic landholders (iqta) and a Jiyza, and the Iqta becoming wealthy off of Jiyza, and then Christian nobles who would have to pay double Jiyza and would be encouraged to convert, who would have to tax the Peasants dearly to hold on. On the Peasants themselves, the lackluster Christianity of the 7th and 8th centuries, combined with at least theoretically being above even Christian nobility if they converted, would lead to many Peasants who are not deeply tied to Christianity converting to Islam. It is very similar to how Judaism was "replaced" by Christianity. Plus there is the whole "we have Jesus too!" thing that Islam has going for it.

 

[Fabius Maximus]

Plus there is the whole "we have Jesus too!" thing that Islam has going for it.

Yeah, but the Islamic understanding of Jesus is totally different from the Christian, given that the Koran explicitly denies that Jesus is God, denies the Christian understanding of the Atonement, and denies the doctrine of the Trinity (which it seems to think consists of God, Jesus and the Virgin Mary).

Even better if they can get the Pope to convert, which is a real possibility.

Contrary to what the collective mind of AH.com seems to think, people in the olden days did actually take their religion seriously, and did believe that apostasy was a very bad thing. The Pope is highly unlikely to convert, and even if he did, the most plausible outcome would be that he's deposed and a new Pope is elected in his place.

 

[John7755 يوحنا]

I think China, or at least parts of China, converting is more likely than Tibet, which had the safety of the Himalayas and practically independent monasteries scattered throughout the mountains. The Steppes eventually did become Muslim, so I don't know why your ATL would exclude them?

The greatest extent I can really imagine is an Islamic Roman Empire stretching from Persia to Spain. I don't believe it could hold together for very long, though, and the early Muslims would need to become amenable to Christianity pretty quickly.

The poster is referring to an Umayyad-Rashidun conquest of the area in the times following Muhammad.

 

[John7755 يوحنا]

This was very optimistic outlook on the Umayyad state in terms of its military capabilities in my opinion.

-Northern Spain and the Basque lands is possible. However, these areas will be extremely isolated. They are not close to any border war, nor do they have the things that attract Arab settlers. This area will likely become an extreme nuisance to the Umayyads to the point of likely letting it go, including the Basque lands. Areas like Northern Spain existed in the lands of Islam, such as the Tabarastan in Iran. Tabarastan was right next to the Caliphal stronghold yet was so rebellious and isolated that it remained little more than a Zoroastrian vassal. Asturias would likely be similar and since you have locked the Umayyad in even more dire military conflict, the area will be lost entirely quite quickly.


-You say no Greek Fire, that seems quite restrictive and roundabout tl to remove its existence. Regardless, the Umayyad could've developed a siege to take Byzantium, however they have a time limit. Umayyads are racing against the clock in every scenario, that is take as much land and hold it down effectively with Arab settlers before the other states wake up and go after them and before they are engulfed in religious wars at home.

Thus, the Umayyads cannot sit and wait on Byzantium at all, it had to strangle it thereby limiting its counterattack, which until later was non existent. The Umayyads could've taken Constantinople under two criteria:

1. If they had a navy that was composed of Arab Muslim who were loyal.

2. They had allies on the other side of the Bosporus.

Both of which counteract the Umayyad ethos of Baqiyyah wa Tattamadad, that is remaining and expanding. The first assumes they have enough time to agglomerate a naval force of Muslim as opposed to otl gathering mostly Copts and Dhimmi who would proceed to mutiny. Second, assumes the Umayyad would ally with anyone or that anyone would ally with them, considering their rapid overexpansion.

Either way, the Byzantines cannot be defenseless forever, and will eventually push the Uqaylids and their Umayyad masters back into the east of Anatolia and begin to compete again over Crete and Cyprus. Especially, since you have put the Umayyads in a worse situation otl, where they are even more warmongering.

- A conquest of France is possible, however, to hold it consideribgbthe time scale for Umayyad life, seems impossible. Gaul also is going to become even more toxic to the Umayyads as it becomes free. It within short order will outpopulate much of the Islamic homelands and have large amounts of troops whereas the Umayyad will only be losing troops. France further as time goes on, will not attract muhjahid as the wealth will not be worth the trouble. Spain was worth the trouble, it was weakened by civil war and not nearly as densely populated in rural areas as Gaul.

-A Umayyad conquest of much of Italy is more possible than a capture of Paris in my opinion. Byzantines are currently being attacked in Anatolia and on the Aegean islands and the powers north of Rome are infighting. In a similar fashion to the Fatimids, the Umayyads could take Sicily wholesale and then link that up with otl capture of Bari and then take Sicily. The only issue with all of this, is that they will be doing all this fighting with less than 20k troops at most. The thin Arab population is going to wane inevitably as it did otl. These areas however can be pushed further north to create a new front to occupy Christian armies while the Muslims better consolidate their hold onto Spain, thereby increasing the likelyhood of survival.

-India is one that requires time. There simply are not enough warriors during the Umayyad Caliphate to fully capture anything past Lahore. Also, the dangerous path to India requires going through the famed deserts in Baluchistan or across the sea. This must be done as the Pashtun highlands of Zabul and the Hindu strongholds of Ghandhara remained defiant. These areas could be taken by the Umayyad considering enough effort is put into it. Once these areas are captured, that is the criteria for the eventual invasion into India using Pashtun warriors increasing army sizes by upwards of 3x the sparse Arab numbers present in India at the time.

Once the wealth of India is found and the vast quantity of idols are discovered, masses of Muhjahid will arrive to fight the war including newly Muslim Pashtun from the Zabul. These wars likely attract all sorts of warriors from Central Asia who convert and look to gain new loot. With this sort of numbers, the Umayyads can break through Lahore and defeat the Rajput and begin moving deep into India in large scale raids. Also, with the Umayyads involved, the coastal raids would become more endemic in this tl with Omani and Yemeni mugjahid arriving in Gujarat by ship to assault the Hindu positions, each tribe and faction seeking to gain more loot, land and idols to send back to Dimashq.

A situation like this however, is assuming the Umayyad survive. However, if this gets started before the Umayyads collapse near inevitably, then it is possible that the warriors involved continue no matter who or what is the Caliph. Which is more or less otl, the Islamic state's of Hindustan existed from Umayyad to Abbasid without serious Caliphal support until the Ghaznavid. (Mind you, otl, it was in the late Abbasid period that the Pashtun were pacified)

Nubia was more or less conquered by the Umayyad. It was simply left alone as it's slave trade was more useful than an actual province. It would not be too difficult to have an Umayyad army push into Dunqula with say 25k troops.

Ethiopia, was considered slightly Muslim at the earliest period. It also was difficult to conquer yet brought in slaves for the caliphate. The Umayyads could continually siege them in their homelands as otl, but considering who all the Umayyads are engaged with, I say conquest is impossible at this date. It also requires much more than an army of 20-35k for a capture of Ethiopia.

The Gokturks are perhaps out of the realm of the Umayyads. Sogdia itself was perhaps out of the way and only barely being touched by the Umayyad and later fully brought into Islam by the Abbasid.

As far as the Pontic steppe, the Umayyads second most intense conflict was here, where they at some points had fought to a standstill and at the end, was defeated allowing Khazar armies to raid all the way from Georgia into Iraq and Syria, so a total route. To capture these areas requires several Umayyad victories that they lost to the Khazar. Another issue the Umayyad had was the sheer size of the Khazar Khaganate which had only sparse resources. Meaning, the Umayyad would invade and raid the entire land, but bring back little loot and destroy little resources while the Khazar warriors avoided them. But while a conquest of the Pontic steppe is doubtful, the securing of Armenia and Georgia is possible if the Umayyad pacify the Christians there and hold off the Khazars.

Tibet is crazy, it would limit the numbers of the Umayyad to a trickle and would have nothing to offer.

There is no possible way to convince any more than 5k muhjahid the wealth of China is enough to travel across the Takla Makan through hostile steppe land harassed by nomads to then meet and army of 100k Chinese imperial soldiers, yea no. You would be more likely to have an Omani fleet capture Taiwan or something similar.

All of this mind you is assuming the internal conflicts that haunted the caliphates do not occur. The ground by the Umayyad Caliphate is already fertile for the conflicts that destroyed both the Umayyad and Abbasid.

It is amazing that the Umayyads are assumed to be able to conquer much more. It had a task far greater than Alexander, a war on so many fronts with little centralization and a state untied under a religion that is a deep minority and made up of heretics who want nothing more to crush your state. It is too big a task to have the Umayyad conquer much more substantially, the best thing the Umayyad could ever do is settle itself and find a way to recover.

 

[LSCatilina]

-The total conquest of Spain is a pretty simple thing for the Caliphate to do once Andalusia was nailed down. The Basque Highlands and the Alps would probably remain Christian for along time, if just because of remoteness.

Spain was totally take on by Arabo-Berbers IOTL, and you had expeditions in the Cantabrians highlands as early as 712 and up to the latter part of the decade.
The problem wasn't the ability of Arabo-Berbers to raid and defeat local armies and nobles, but to keep them in check : they simply lacked men to really control most of the land in northern part of the peninsula (at the exception of the lower valley of Ebre) giving that by 750 (with the addition of Syrian djunds from Ifriqiya, then), Arabo-Berber presence in al-Andalus may not have been especially important numerically : maybe some thousands.

It's really obvious with how Arabo-Berber managed the gothic province of Gaul : north of Pyrenées you had maybe 2 or 3 garrisons at best (ca. 735) all the remaining part of the region being under very technically subservient Gothic nobility (which didn't have much issue switching sides).

Really, it's not a matter on how Arabo-Berbers could reach northern highlands, as they did IOTL. It's about how they could control it, and how they could really manage to hold it in face of the Great Berber Revolt (which will happen, sooner or later, in the early VIIIth) which was a cause of the abandon of northern ribat and garrisons.

At the leatest, you'd need reinforcements and a better treatement of Berbers by Arabs, especiall considering they formed the bulk of Islamic forces. Giving that all caliphal edicts on luladi were troughly ignored by Ifriqiyan walis and ther clientelized emirs and walis (Ifriqiya turned more or less as a vice-royalty for Islamic West since the early VIIIth, a marginal region for what mattered Dimashq)

Constantinople was commanded by Muhammad himself to be conquered, and was besieged many times. No Greek Fire and a bit more administrative stewardship to avoid a civil war could have easily lead to Constantinople have fallen.

The problem of the sieges of Constantinople are less the Greek Fire (it wasn't present systematically) but the absence of a fleet able to take on Roman naval capacities (and supply lines) even in the VIIth century.

They essentially, at first at least, borrowed on the local naval tradition of conquered regions : the battle of the Mastes was mostly fought by Syrian and Egyptian sailors for what mattered the Rashidun's command. The byzantine campaigns in 660's had as an objective to free most of syrian or egyptian harbours (by supporting local revolts, for instance) because it was where a Caliphal naval power could rise.
Note that they didn't really defeated the Roman navy on the long run, in spite of deserved victories : the failure of the Arab sieges of Constantinople for instance, owes a lot to their unability to really break the naval strength of the empire, aka the supply line.

The Frankish Empire was really just kind of a group of Barbarians until the defeats of the Muslims by Charles Martel and Charlemagne.
Plus, parts of southern Toulouse were occupied at one point. A series of Frankish defeats, especially if some ambitious nobles converted to Islam to advance their position, could have left the Caliphate on the offensive in Paris. Just how far the Islamic armies could have marched into France and Germany is really dependent on how resistant is the population is.

I think this is particularily incorrect and, to say the least, flawed.

I won't go into details, but I strongly advise you Bachrach's Merovingian Military Organisation, as a study pointong on how the Frankish army was organised, and strong enough by the early VIIIth to not be considered as "a group of Barbarians".

As for the part of Gothia, Aquitaine or Provence occupied in the 720's-730's, again, we're talking of a particularily light-weight occupation with a couple of garrisons at best and no trace of Islamic presence outside Narbonne/Arbûna.
Does that means that Arabo-Berber raiding wasn't a thing in the period? Of course not, but people bound to say that after Tours, they would have gone even northern conveniently forget that Arabo-Berbers DID reached the outskirts of Paris' region before Tours, in 725 when they raided Sens. Surprisingly, it didn't went the way of a Franji emirate, because it was not the point of the campaigns to begin with.

I'm not saying you couldn't end up with an occupation of southern Aquitaine in the 720/730 tough, but it would likely go the way of Gothia : a really limited Arabo-Berber presence which would be importantly weakened by both Frankish intervention AND the pretty much unavoidable Berber revolt that would deprive local armies from the main part of their forces.


I think half of your problem is you consider the Caliphate as some sort of modern state, where raids and invasions (you do seems to confuse raiding campaigns and actual invasions as well, but that's another issue) are planned and ressources distributed. In fact, at least for what matters the Islamic West, Islamic campaigns are mostly a matter of local and private initiative (while still subservient to Dimashq) that had to count on their own forces : Arabo-Berbers had enough trouble swallowing up Spain (you had actual talks in the 720 about just giving it up) because of the absence of another recruitement pool outside Maghrib (there's no big mystery if the occupation of Spain happened when Maghrib was pacified).

I stress this again : past the Ebre, Islamic garrisons are rare stuff, and it became exceptionnal past Pyrenées. Arabo-Berbers simply didn't have the numbers to undergo an invasion that would have been clearly harder than Spain (mostly because of a more powerful, unified and ressourceful Frankish regnum compared to Gothia : Peppinids managed to enforce their hegemony pretty well as hinted by the short civil war of 714-718)

 

[Falecius]

I agree that it's hard to see the Rashidun/Umayyad domains stretching much more than they did historically and keep the new conquests consistently. Anatolia may be a possibility (though it's hard) and some better results in Afghanistan/India or against the Khazars are also possible, but the limits on manpower, logistics and administrative capacity would be reached fairly soon.
Nubia did defeat the early Islamic incursions militarily and then had the wisdom to reach a mutually convenient agreement. They could have been taken fully perhaps, but I don't see the Umayyad rule going anywhere further from there.

 

[LSCatilina]

For what matter Khazars, Ummayads did scored victories IOTL, especially with the treaty passed in 737.

The khagans seems to have converted to Islam during Marwan's rule in the aftermath of the Second Umayyad-Khazar war as part of the negociated peace (at least locally, it's not entierly clear if we're talking about the khagan, a tarkan or a local lord, while I'd favour the two first).
It's apparently coming from al-Baladhuri, as follows.

Marwan as governor. Marwan ibn-Muhammad * then became the ruler of the frontier and took up his abode at Kisal. Marwan was the one who built the city of Kisal.
This city lies 40 parasangs from Bardha'ah and 20 from Taflis. Marwan then entered the country of al-Khazar next to Bab al-Lan and made Asid z ibn-Zafir as-Sulami abu-Yazid, accompanied by the kings of al-Jibal, enter it from the side of al-Bab wa-1-Abwab. Then Marwan made an incursion on the Slavs who were in the land of al-Khazar and captured 20,000 families whom he settled in Khakhit. When they later put their commander to death and took to flight, Marwan pursued and slaughtered them.

When the chief of al-Khazar learned of the great number of men with whom Marwan had swept over his land and of their equipment and strength, his heart was filled with cowardice and fear. When Marwan came close to him,
he sent him a messenger inviting him to " Islam or war ", to which he replied, " I have accepted Islam. Send therefore someone to present it to me."

Marwan did so. The chief professed Islam and made a treaty with Marwan according to which Marwan confirmed him as ruler of his kingdom. Marwan with a host of al-Khazar accompanied the chief; and al-Khazar were made to settle in the plain of the province of al-Lakz between as-Samur and ash-Sha-
biran.

It could be one of the explanations why Khazars didn't resumed raiding and campaigning in South until the Abbasid coup.

I could imagine a TL where Khazars would remain more or less islamized (as they were more or less judaized, meaning not too much) : either an Umayyad maintain (I'm not too sure about it, tough) or an earlier Abbasid-screw meaning that adopting Islam becames less of a subservient marker.

 

[water123]

Huh, so the consensus seems to be that (outside of India possibly) the Caliphates themselves really could not have gotten larger than they did, and if there was a conquest of, say, Frankia, it would be by an independent entity into a fractured land (i.e. no large state in Frankiaa, or invading just at the end of a brutal Byzantine civil war)?

 

[Falecius]

Huh, so the consensus seems to be that (outside of India possibly) the Caliphates themselves really could not have gotten larger than they did, and if there was a conquest of, say, Frankia, it would be by an independent entity into a fractured land (i.e. no large state in Frankiaa, or invading just at the end of a brutal Byzantine civil war)?

They could have gotten somewhat larger, but probably not significantly so. And the larger they get, the quicker they are likely to fracture.

 

[water123]

They could have gotten somewhat larger, but probably not significantly so. And the larger they get, the quicker they are likely to fracture.

To be fair, i assumed it would fracture. I wasnt wondering how long itd last, i was just curious how far it could spread Islamic influencs

 

[John7755 يوحنا]

@LSCatilina The Umayyad perhaps won the war by name but tactically, it was a Khazar victory in the same way that the Byzantines won the Byzantine-Umayyad conflicts simply by being less harmed. Otl showed us that the Umayyad could not afford Pyrrhic victories. Further, no matter the enventual result, raids into Iraq did not assist the Umayyad legitimacy especially among the eventual Abbasid supporters in Iran and Iraq.

 

[LSCatilina]

Oh, I agree. But there was room for an allohistorical caliphal dominance over Khazars (especially if these pull and Avar in the VIIIth century and cease to really control peripherical khanates as Bulgars')

 

[Isfendil]

Honestly if you want it to expand to a much more significant degree, you'd have to weaken their opponents considerably. Make the job easier, you know? I mean they spread very far. The extent of Islam so soon after its rise was absolutely unprecedented- that it actually remained a cohesive polity for any substantial amount of time, let alone 1.5 whole dynasties (latter Abbasid doesn't really count anymore), is downright spectacular.

 

[Max Sinister]

Yes, they were very successful IOTL already. Hard to see how to give them even more success. And their biggest enemies (Persia, Byzantium) were already weakened.

 

[Planet of Hats]

Spain was totally take on by Arabo-Berbers IOTL, and you had expeditions in the Cantabrians highlands as early as 712 and up to the latter part of the decade.
The problem wasn't the ability of Arabo-Berbers to raid and defeat local armies and nobles, but to keep them in check : they simply lacked men to really control most of the land in northern part of the peninsula (at the exception of the lower valley of Ebre) giving that by 750 (with the addition of Syrian djunds from Ifriqiya, then), Arabo-Berber presence in al-Andalus may not have been especially important numerically : maybe some thousands.

It's really obvious with how Arabo-Berber managed the gothic province of Gaul : north of Pyrenées you had maybe 2 or 3 garrisons at best (ca. 735) all the remaining part of the region being under very technically subservient Gothic nobility (which didn't have much issue switching sides).

Really, it's not a matter on how Arabo-Berbers could reach northern highlands, as they did IOTL. It's about how they could control it, and how they could really manage to hold it in face of the Great Berber Revolt (which will happen, sooner or later, in the early VIIIth) which was a cause of the abandon of northern ribat and garrisons.

At the leatest, you'd need reinforcements and a better treatement of Berbers by Arabs, especiall considering they formed the bulk of Islamic forces. Giving that all caliphal edicts on luladi were troughly ignored by Ifriqiyan walis and ther clientelized emirs and walis (Ifriqiya turned more or less as a vice-royalty for Islamic West since the early VIIIth, a marginal region for what mattered Dimashq)

I've always viewed it sort of this way: The Umayyads going any further than Iberia isn't going to be a thing in any TL that does not avert the Berber Revolt. Even then, pushing the Umayyad super-caliphate past Iberia is a tough call and requires some luck or some really incompetent opposition. Even as early as 718 or 720, there was some consideration by the then-current caliph of pulling out of al-Andalus because of how dicey the situation looked for them in terms of numbers.

I've read up on enough of your commentary on al-Andalus over the years to at least take that much to heart.

Honestly if you want it to expand to a much more significant degree, you'd have to weaken their opponents considerably. Make the job easier, you know? I mean they spread very far. The extent of Islam so soon after its rise was absolutely unprecedented- that it actually remained a cohesive polity for any substantial amount of time, let alone 1.5 whole dynasties (latter Abbasid doesn't really count anymore), is downright spectacular.

Even then, you're going to have a hard time actually keeping a lid on the populations you absorb. Andalusia was the western edge of the Muslim world at the time and you still have to cope with the problem whereby you're a minute population of Arabo-Andalusians with a modest army of dubiously loyal and surly Berbers and Arabo-Berbers trying to keep a lid on a population of mostly Iberians who don't like you very much at the start. There was constant unrest and rebellions weren't uncommon even a couple of centuries later. There was a big Muladi revolt that dragged on for a few decades in the 880s and on into the 910s, for example, and you still had to deal with Berbers who would come to the cities and become very uncomfortable with urban life, saying nothing of being viewed by Arabo-Andalusians as their inferiors.

If you're going to have any chance at more of Europe, you'll need more reinforcements, better treatment of the Berbers to avoid the Berber Revolt, and probably a weaker Frankish complex. Even then, Aquitaine might be realistic, but you're still pushing really, really hard. Either that or you need to find some other reliable source of troops that isn't a bunch of Berbers who think you're too decadent and treat them like dirt.

 

[John7755 يوحنا]

One reality we should realize, what even was the extent of Umayyad control of the Semitic and other Mid East lands?

The Umayyads only had tight control over the following areas:

Shams (Syria, Lebanon)
Palestine
Egypt
Northern Iraq and Western Iraq
Hijaz
Nejd
Haasa/East Arabia
Oman
Yemen

I would argue that everything else is only held up by the force of Muslim warriors.

The Abbasids would settle themselves unlike the Umayyad with essentially their goal of reigning in the Islamic world and it still all collapsed with 200 years. This in my opinion is doomed if the Umayyad are pushed to expand further, and it could have the adverse effect of a Byzantine resurgence in Syria if things are not taken care of.

 

[Fabius Maximus]

TBH I think the Caliphate was already larger IOTL than could reasonably have been predicted before its rise, and its expansion relied a lot on weakness among its enemies (the Byzantines and Sassanids both being exhausted by a quarter century of war, the Visigoths of Spain being in the middle of a civil war). With a bit of luck the Caliph's armies could have taken Constantinople, after which Anatolia and Greece would probably have fallen, and they could probably have taken Sicily and southern Italy too, but that would be about it IMHO. The Franks would be too strong and too far from the Caliphate's heartland to subdue, and any conquest of Italy would probably just lead to the Franks getting involved and taking over the area as they ended up doing under Charlemagne anyway. Meanwhile the area north of Greece was quite mountainous, and IIRC quite underdeveloped as well, which would make conquering it difficult and not really worth the effort (think Romans in Germania for a parallel). I'm not so sure about the situation in India, whether there was more scope for expansion there, but at least in the west I think opportunities for extra conquests would be limited.