Wondering why this is? I always get screwed over by the AI and the titles pass from my realm. Is it because I was a count? If I were a duke would I have remained independent?
Even if the emperor hates you, it's easier to fight in rebellion than it is against the united empire.In this vein I almost always elect to be a vassal of the Abbasids and emerge with Persia and most of Mesopotamia as Zorastrians.
As opposed to being Holy Warred into oblivion.