What baffling is that the Great Conquering Muslim Empire couldn't really do anything against Byznatium. They stripped the Romans from the provinces on their perifery - I guess imperial grip was weak there - but couldn't crack the real nut. Meanwhile the Sasanians fell like wheat by a scythe. All right they couldn't puncture a hole on the Frankish defense on the very far side of their territories, but Byzantium was in their mouth, a literal neigbour of the core of the Caliphate.

>>18494
>If (for some reason) they were able to win, I'd wonder how they'd do against Wessex or the Saxons.
I think they would have did fine. On the British isles they were too little kingdoms with too little manpower. Not Northumbria, not Mercia, not Wessex in their peak could have stood a chance. Continent Saxons were beaten by the Franks for 200 years by the 8th century, if they could beat the Franks, Saxons wouldn't be a problem.