I actually invaded the Papal States once as England after I got excommunicated when I attacked France
I actually posted this in another thread, but when the new pope got elected (Following the untimely death of the last one), he exclaimed that "The flames of eternal damnation" are too good for me
Lemme find that screenshot...
EDIT:
Not sure if this was because I killed the last Pope or because I didn't vote for the new guy