
Demand them to convert and if they refuse you can imprison them. To deal with this we can do almost the same thing to the muslim prisoners. Heresies are a huge pain in the ass because when vassals join a heresy they convert the county to that heresy as well. Lastly, if you get a bad bishop with a terrible learning skill it may be worth to assassinate him because having a bishop with a poor learning skill can drastically increase the time to convert counties. It really cuts down the time it takes to convert counties. I personally get religious icon (in the theology tree on the lefthand side) skill point on every ruler as fast as possible. When they convert to Christianity they will will convert the county with them. Then give that muslim a muslim controlled county and use that weak favor on them to convert to Christian. As you play through and conquer hopefully your prison will be filling up with those filthy muslims infidels! An easy way to quickly convert counties is by negotiate release with muslims prisoners and making them join your court and gaining a weak favor on them. You are very weak in the beginning so having france as a ally helps a lot. I started as King alfonso in 867 and before anything happened I married the king of france's daughter. I went for this on my first playthrough because i loved playing as spain in CK2 so i naturally just went for it. Just to state the obvious, Christian heresies do not count as Christian.

You need to control ALL of Spain, have it be Christian, AND you need to control the duchy of Barcelona despite it being de jure to france.


Despite it saying "Starting as an Iberian Christian, convert all of Iberia to Christianity" there is a little more to it. Let me clarify one thing about the achievement before we start. This isnt going to be a full depth play by play guide but more of a the basics of making this as painless as possible.
