This question was inspired by my Frankish campaign in the "Age of Charlemagne" expansion for "Total War: Attila," where I had the Franks take over the last Cordoban possession in 799 or so.
Leaving aside the question of whether or not such a feat would actually have been possible, I'm interested to know what the long-term effects might have been. Since Charlemagne's empire was divided among his sons after his death, it can be presumed that Iberia would eventually become separate from the other regions that would eventually become France, Germany and so on, so no super-France or anything like that. But I wonder how Frankish control and a far shorter period of Arab rule might affect such things as languages, for example, considering that the oldest surviving records containing written Galician-Portuguese are documents from the 9th century, whilst Spanish as a language didn't yet exist as such at the time as people spoke Castilian, Leonese, Basque and Catalan.