I must say this is pretty ingenious. In my previous campaign, which I abandoned, both the HRE and Genoans were being a real pain in the butt attacking me for no reason (I wasn't ready to assault my neighbors just yet).

With this tactic, you can jump into their nearest province, sack it, and then give it to the pope.

Even better, give it back to THEM and then sue for peace! LOL.