Manorialism is a system of vesting property in a lord of the manor, who had jurisdiction over subject peasants. The system was based on mutual obligation and benefit. The king or some other high lord gave the use and benefit of the manor to the lord of the manor in exchange for military and political support. The lord of the manor gave the peasants a place to live, fields to farm, and protection in exchange for labor, part of the crop, or other economic support.
Their lack of an industrial revolution made them unable to procure all the items they needed by themselves.
The answer to this question is C-trade rights.
