Quote Originally Posted by Horatius
Why does sending your King to take the abandones/unconquered place hurt your king/you?

I would think that the easy victory and newly gained glory would advance your cause.
There seems to be a bug which causes a king invading enemy territory is considered cut-off from his own countries (even though he just in the province next door): this can cause a big loyalty drop if your king has high influence. It is especially bad, when invading an island province because oftentimes the port gets destroyed so the king is completely severed from his homelands. Many an English king lost his kingdom to rebellion while he was stuck on Ireland (in game, not in history).