Quote Originally Posted by Ludens
A faction will always pay the King's ransom if they don't have a heir to take his place (or if you have captured that heir too). Katank has based a Turkish strategy on isolating and ransoming the Egyptian Sultan several times by taking Tripoli.
But a ransomed King gains a 'captured vice' which lowers command but seriously increases morale, so be aware: he and his men will be less likely to rout next time.
Thanks, Ludens - I've been perplexed about that for a while. Another mystery solved!