Finally!

[Sebbe]

I now have 106 settlements! It is just me and Papal States left, and I just wonder if I have all settlements now?

I have 15 turns left.. What to do? Kill the pope 15 times more?

[Antonidas]

that amount of turns doesn't really end the game. I've gone past that and into the 1600's before. if the papal states are still there, they must have a settlement. find it! destroy them! also, have you discovered the new world yet?

[Adamat]

^Untrue. The Papal States cannot be destroyed. You do have all the settlements, and the game is now pretty much over. Time to try some mods!

[Kahath]

I now have 106 settlements! It is just me and Papal States left, and I just wonder if I have all settlements now?

I have 15 turns left.. What to do? Kill the pope 15 times more?

Congratulations, you have all the settlements in the game. The Papacy cannot be destroyed, although it can be effectively broken if no cardinals are available for papal promotion. Out of curiosity what faction where you playing as?