Crusader Kings II

[Dab]

And Dab, holding bits of Spain isn't nearly as hard as holding jerusalem... Trust me on that. Also, dishing out the titles properly means you can get the population converted pretty quickly.

Yes, I know, that's why I never try to take Jerusalem.

Religious conversion depends on time, moral authority of the church, and your Court Chaplain. Title giveaways don't worry change it. However, any vassals you place in that territory that is of your own religion will send their court chaplain to convert as well. So vassalized provinces CAN convert faster depending on that, than Demesne ones, because you can combine your court chaplain with theirs.

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