How do you destroy the papal states in medieval 2 total war

it is impossible to defeat the papal states unless there is no pope but there is ALWAYS a pope by the end of a turn.

Even if you conquer every region on the map, destroy every papal army and conquer every papal region the pope will still exist.

I once conquered every space except rome. The PS had a big army in my Marseille region. I conquered Rome with one army and killed the pope. The next turn I was auto reconciled and the pope appeared in the army in Marseille. I killed that army and left nobody alive. At the end of that turn there were NO PS regions or armies anywhere. The next turn the pope just appeared in the rome region.

Im going to try killing all the inquisitors as well.