This is frustrating when this happens. In my current Early English campaign, I am the largest by some way. I have conquered all of Islam single handed, pushed Byzantium into 2 small Islands and have been waging war against the Novos for ages. I haven't been near the Hungarians, but they attacked 1 province of mine - Moldova I think - I lift the seige and I am currently under threat of excomm - ther is no justice!! Nobody wants to ally with me either. I have even given the Pope Burgandy after he bribed a rebel army to his side.