Ok, this game just went full crazy. The abbassid badshad (jewish) inherited the sunni caliphate from one of his vassal. So the religious head of the sunnis was jewish. And when I declare holy war on him (I wanted to unland him to be able to claim the sunni caliphate), all other sunni sultans (Africa, Egypt, Persia and Arabia) refused to join (religious head modifier

). I got my ass handed to me in the desert (at the border africa/egypt), since I had 2 split stacks of 12k to avoid attrition. Anyway, I lost that war, assassinated a dozen abbassid badshah to cause unrest and lo ! there was a survivor sunni abbassid. Meanwhile, there was a huge civil war still in that empire. So, I won't get the sunni caliphate any time soon, but at least we'll have jihads and MA and stuff.
So, get back to Andalusia, I kinda want to grab the Africa kingdom. Wait, what's that ? It's a republic now. Yup, Aghlabid Sultanate is a republic now.
On a less crazy note, a Capet rose to the throne of Aquitaine (ok, it's kinda like, half of Aquitaine, the other half being split between East Francia and Bavaria, but it's already a step !).