Hey Tony! Kavhan Isbul has got the right idea. Just invade Cordoba (or whichever province you choose, but Cordoba is ideal for this situation), and then wait for the Caliph to launch a counterattack against you. I've also found that for best results, you should lay siege to the castle instead of directly assaulting it--this gives the Almos a little extra time in which to prepare their counterstroke against you.