During the 700s most of spain was conquerored by the

Ummayad caliphate. It might sound arcane or intimating, but look at Nithard's Royal Frankish Annals. It consists of something like a diary entry for each year after the death of Charles Martel, and each entry is pretty straightforward and not over-full of detail. It is quick to read and gives an interesting rundown of the wars of unification that Charlemagne waged, and it gives you an idea of the different Muslim states in Europe. Spain was one of those, the Avars were another.