For everyone who hates the Pope:
I learned this on my own and some of you guys probably already know this. But if you go to Papal states and offer them alliance, the pope falls in love with your faction. Then during the same turn, give them a map (The Pope doesn't get around much) So he will be even more delighted to raise your faction to be the top Holy faction in the first 10 turns.
All you have to do is give them something every 20 turns because the crosses drops every once and a while. And if one of your enemies gets excommunacted. You can call a crusade against them with no problem since your the Pope's best friend.
Problem with this is that the Pope dies too many times but i offered the new Popes 100 florines for 10 turns and he raised me to the top from 4 crosses.
And thats not alot if your a rich faction