Does anyone know whether you keep any prisoners you've taken when you loose a battle? To futher clarify, I mean when you were winning a battle and taking prisoners and the tide of the battle turned and you lost it, do the prisoners you've taken remain in your custody?

The reason I ask is I once recently invaded and was defending northern irelandwith the picts with about 1200 soldiers against maybe 2000-3000 or so. I lost about 900 and killed about 900 but I also took 1000 prisoners before the fight ended. Finally the re-enforcements beat me because I guess, I left my half of the map and spread myself really thin, plus my troops were exhausted. I can't remember whether I could ransome the prisoners or not.