Slezh), then the lord who owns the castle will become your enemy with a relation of -25, and you will not be allowed to enter the castle. Regardless of the method in which you joined the faction, the king will grant you the poorest village his faction currently possesses. If you ask the king yourself, certain calculations are involved to determine whether you are worthy of becoming a vassal (refer to joining a faction for more information).
Factions you have negative relations with will not offer allegiance. If you refuse an offer you will lower your relations with the leader offering it, making him less likely to make a future offer once his opinion of you is a negative value he will stop asking you.
Once you have at least 150 Renown, kings will start randomly asking you to pledge your allegiance, offering you a village to sweeten the deal. For more information, see the factions page. Holding a fief on your own is difficult because the other factions can declare war on you at any time and will arrive in force to take your lands from you. If you besiege a town or castle when not in a faction it will automatically become your property at the end of the siege.