I am about to take the city with Apostolic Palace and wanted to know since it is different religion than my state religion, can AP change religions and how many turns until it does?

I will move my missionary in first turn after I capture the city, if that makes any difference.

I am about to take the city with Apostolic Palace and wanted to know since it is different religion than my state religion, can AP change religions and how many turns until it does?

I will move my missionary in first turn after I capture the city, if that makes any difference.

AP religion is permanent and is whatever the state religion of the builder was, at the time of construction.

Then it would be dandy if i could slaughter all their delegates then when they declare collective war on me after I take AP, but before they can run safely home.