So, I have the delightful pleasure to marry off my non-heir son. One of the options is a courtier in the Papacy with less-than-admirable attributes. Still, it sound like a fun thing to do. Has anyone tried this? Is it any different from any other alliance?
I imagine that the Pope would attempt to bugger me into joining any of his little disputes … and that he'll likely not give much help in return.
(Plot twist! It's actually the legitimized bastard daughter of the Pope himself and some lowborn promiscuous lady.)
Best Answer
As others have pointed out, essentially nothing. You may or may not be able to call him into wars, and he may or may not do the same.
Interesting thing happens though if you're an emperor-tier ruler and have an anti-pope installed. You gain a CB to install your anti-pope, and if successful can vassalize the pope (assuming you have a de jure claim or the anti-pope is of your dynasty, as usual).