And as most of your army will come from what your vassals volunteer you, hacking them off is one of the fastest ways for a king (or duke) to lose his crown, much like in the original game. Vassals, then aren't something you can get rid of. Realm Tree of the Holy Roman Empire (Vassal-Liege feudal relationships). You need vassals because of your demesne limit, or more prosaically, because your liege can't be everywhere at once and things would fall into chaos. Your vassals are the nobles who help you run your lands (in exchange for being able to establish a power base within those lands) and allow you to administrate the realm and raise armies and tax from that realm without everything going to pieces. 5 A Word of Warning for Would-be Warmongers.3.1 The Stuff You Can Do Something About.