What if Islam Conquered Europe (or, at least, present-day France)?

[Frodo]

Let's suppose that the battle of Tours was avoided simply if the Muslim commander, Abdul Rahman al Ghafiqi had done his due diligence and conducted reconnaissance, and been made aware of a potentially formidable enemy to his north.

How differently would history have unfolded?  What if he had taken the fight directly to the Prince and Duke Charles Martel on ground (and at a time) of his own choosing?  With the Franks the only force capable of resisting the Muslim tide, what if they had succumbed as the Visigoths had done earlier in Spain?  Would we be talking Al-Andalus writ large across the continent?  Or following the Roman example after conducting raids beyond the Rhine throughout the continent, the Muslim invaders would have been content to remain in the Iberian peninsula?  Maybe turned their attention to Italy, then being fought over between the Lombards and the Byzantine Empire?    

[Frodo]

I doubt that the Muslims would have conquered Europe because they were already very overextended. After conquering France, where do they go next? If they go to Germany, they are going very deep into Europe and overextending themselves even more. As far as I see it, the deeper into Germany they go, the more they expose themselves to enemies, I could see them making a lot of progress but I don't think it'd last long. Italy is better protected with the Alps and the terrain is more mountainous. That said, I could see permanent Muslim strongholds surviving in Italy for centuries, and not just Sicily. Britain at the time wouldn't really be worth invading, although it could be a threat to Muslim France to have an untouched Christian stronghold across the sea. Plus as the Vikings rise, Muslim Europe would face even more pressure.


Long term, the main problem for Muslim France is the defensibility of its borders. The Alps are good, but the whole north-east is exposed to the North European plains. All it would take is a strong power to rise in Germany and for Muslim armies to be occupied elsewhere and northern France would likely fall.

How would a strong power rise in Germany, though?  Bear in mind that the catalyst for the creation of the Holy Roman Empire (aka, the First Reich) were the conquests by the greatest Frankish king in history, Charlemagne.  Absent that, who would take his place with the Franks subsumed in an expanded Al-Andalus?  Even in OTL, it took centuries for the squabbling Christian kingdoms in northern Spain that fought each other at least as much as they fought the Muslims to eventually retake the peninsula.  And there were rarely more than a handful of them.  

Imagine how much longer it would take for the even greater number of feuding Germanic tribes to reduce the Muslim presence in France to the Mediterranean region, if they even made it that far.  

No, I think we would see a Muslim France and Spain (not to mention Portugal) surviving to this very day.