I saw Papal States conquered and annexed many times, but it's ridiculous! I know that sometimes Papal states were defeated, occupied in this period but no one dared to annex them and expell Pope from Rome! It became possible only in time of nationalism, revolutionary ideology etc.
Firstly all rulers who attack Papal States should be automatically excomunicated ( if they are catholic), secondly after annexation there should be event for conqueror to give back Rome province, if rejected it should give very high opinion penalty with all catholic rulers, there also should be special casus belli for all catholic countries to declare war to liberate Papal States.
Finally decision to unite Italy shouldn't require Rome! Historically Italy formed without Rome, and they had capital in Florence. There were also catholic who wanted united Italy but oppossed conquering Rome.
Firstly all rulers who attack Papal States should be automatically excomunicated ( if they are catholic), secondly after annexation there should be event for conqueror to give back Rome province, if rejected it should give very high opinion penalty with all catholic rulers, there also should be special casus belli for all catholic countries to declare war to liberate Papal States.
Finally decision to unite Italy shouldn't require Rome! Historically Italy formed without Rome, and they had capital in Florence. There were also catholic who wanted united Italy but oppossed conquering Rome.
