Well I'm just glad to know I'm not getting a false impression of the AI here. I noticed Human/AI relations falling during my Hard campaign but I honestly thought that would happen even in Easy, didn't know it was difficulty specific. Frankly I don't see how a defensive campaign on Hard/Very Hard could possibly succeed (Unless your say, England).

I do have two pertinent questions though. I find the AI in some cases will attack me immediately if I take a rebel province it wants. I.E. the Byzantines will drop everything and send all their stacks to Sofia if I take it, neglecting rebel territory like Durazzo, Smyrna and Rhodes. The Sicilians will send all their military power to Cagliari if I take it before they do as well. They forgo Tunis, or the aforementioned Durazzo and send all stacks to Sardinia first. Is this a feature? Secondly, I find the AI likes to arrange Vassalage agreements only to attack one or two turns later. This is not strictly historically accurate and I also don't understand why the devs wouldn't give the AI sense enough to know that you don't attack your own vassal right away, is this also a feature? Anyway, merry Christmas!