Just tried it and no. The county left my realm rather than the duchy joining it. So it seems I have to give him a title that is equivalent or higher to the one he's inheriting for him to become part of my realm.
So if I were an Emperor, say, and I was supporting a vassal in their claim for a Kingdom, I'd have to give them another Kingdom for them to become part of my realm? That seems...excessive.
I believe that if the Kingdom is a de jure part of your Empire they'll still join you. Alternatively, if you press the claim of a dynasty member they'll also join you.
« Last Edit: April 16, 2013, 12:14:36 AM by Norrel »
Logged
“it was never wise for a ruler to eschew the trappings of power, for power itself flows in no small measure from such trappings.”
- George R.R. Martin ; Melisandre