The Brotherhood of the Blade is a secret guild of vigilantes, bringing justice to the land when the corrupt king fails to do so.
There is an Overseer for each settlement. This person is responsible for (in the real world) creating his assigned settlement. In the lego world, the Overseer is responsible for knowing what happens there, and informing other members of crime and wrong doings.
Tenets of the Brotherhood:
First Tenet: Discretion. Let no one know of your deeds other than your brothers and your victims.
Second Tenet: Humility. Do not think yourself higher than others. We are all human.
Third Tenet: Reality. When facing your victims, let them know of their wrong doings, and make sure it never happens again.
Fourth Tenet: Restraint. Do not let an innocent come into harms way by your doings.
Fith Tenet: Justice. Uphold the law. Punish those who have wronged others.
Sixth Tenet: Protection. If it is in your power to prevent harm, do so.