http://en.wikipedia.org/wiki/Al-Andalus
Ah yes, Muslim Spain, that worked out well...
I was wondering, if any way an Islamic Spain could've taken power in Spain. The Christians weren't persecuted in the Caliphate of Córdoba, nether were other religious minorities. Maybe if the Reconquista failed in some way, or if Spain was weakened all by itself, maybe it could've survived. I'm not asking for a way for it to survive, but at least stay around enough to mess up the Age of Exploration, and maybe weaken Spain permanently.