Quote Originally Posted by Caerfanan
It might be that when warned by the pope, if you are fighting christians two turns after the first warning, you're excommunicated? I had it work "normally" for me allways, but I tend to fight one christian at a time!
The Pope doesn't care if you wage war against Orthodox factions (Byz, Russians/Novgorod). If he warns you to stop warring with a Catholic faction, however, and you refuse to comply within 2 years, then yes you'll be excommunicated.