AHC: muslim Sardinia

are there any plausible PoD's for the island of Sardinia to remain, religiously, majority-muslim until at least the late modern age?
Why didn't the most powerful medieval muslim states like the Umayyads, Cordobans, Fatimids and possibly the sicilian Qalpids bother conquering the island? On a map, it looks as equally close to Africa as it is to Europe. I heard the Ottomans had plans to conquer it before their defeat at Lepanto.
 
Why didn't the most powerful medieval muslim states like the Umayyads, Cordobans, Fatimids and possibly the sicilian Qalpids bother conquering the island? On a map, it looks as equally close to Africa as it is to Europe. I heard the Ottomans had plans to conquer it before their defeat at Lepanto.

I would imagine it's because the powerful medieval Muslim states had higher priority (read: wealthier) places to try and conquer. I can see a Muslim Sardinia in one of two scenarios. The first is that mainland Italy is taken by a Muslim state, allowing them to then focus on subduing the more out of the way Sardinia. The second, which is less likely to last, is that the area is conquered by Muslim pirates, in a similar fashion to the Emirate of Crete, and is gradually Islamized and held to the present day. The second scenario is less likely to last because OTL most of the "Muslim pirate enclaves" such as Crete and this one in southern France that I forget the name of were ultimately reconquered pretty swiftly.

I have not heard of the Ottoman attempt at Sardinia, but if true, they might be able to conquer it, however I think that in general the Ottomans Islamizing a population tends to be the exception to the rule rather than the rule (see: Bosnia and Albania vs the rest of the Balkans) so you'd have to come up with a plausible scenario where the Sardinians are Islamized.
 
There was at least one major attempt to conquer Sardinia in the early 11th century by one of the Andalusian taifas. It failed because ultimately Sardinia is a lot closer to Italy and the various powers there (in this case, Genoa and Pisa) than it is to the major Muslim power centers.

Your best bet is a much more successful Al-Andalus, which can afford to launch those sort of campaigns, and is likely to leave the nearby Christian realms with more important things to worry about.
 
Mujahid's problem was that he was too late. By 1016, the Christian maritime republics were strong enough to oppose such operations. An earlier fragmentation of Andalusia might allow someone like Mujahid to appear earlier; alternately, a different Italian situation which strangles Pisa/Genoa in their cribs could do the trick.

The problem with entrusting this expedition to a stronger Andalusia is that it's simply not a high priority. Why would you pay attention to Sardinia when the Christian kingdoms are right there, on your border? In contrast, Mujahid's state (Denia-Mallorca) was a coastal-facing principality whose only infidel "neighbors" were over the sea. Of course, nothing stops the taifas from fighting each other instead of Christians, but Mujahid's invasion was also a matter of legitimacy: as a "saqaliba," a former slave of Christian/Slavic origins, it was critical that he legitimate himself as a ruler. He produced his own puppet Caliph and attacked Sardinia to demonstrate his commitment to jihad and to establish himself as an "emir by conquest" who had expanded the house of Islam. A strong Andalusian Caliphate doesn't need to "prove itself" in this way, and if it does gain a renewed taste for holy war Sardinia is hardly the most likely target.

As for the Muslims of Africa, they could potentially have managed it in the 9th century, when Sicily was being conquered IOTL. Perhaps if Sardinia, rather than Sicily, was the site of a Byzantine rebellion, Sardinia would have been conquered instead. Sardinia, however, has a long history of resistance in the interior - even the Romans had trouble with the Sardinian natives - and the Africans might have some difficulty fully pacifying and settling the island. Even if they manage it, it's very likely to fall back into Christian hands by the 11th-12th centuries unless Italian history is substantially changed.
 
There's also another problem Sardinia are a poor mountainous island. If the Muslim conquer it, they will only conquer the lowland, with the Christian retreating to the mountain. So we will end up with a rich Muslim lowland and poor Christian highland, that's a recipe for the moment the Muslim show weakness the Christian clans will come down from the mountain, and unless the Muslim keep naval dominance, they won't be able to get support from abroad. So you pretty much need a Muslim dominated Mediterranean to keep control over Sardinia, as it simply lent itself to the natives retreating into the mountains.
 
Top