Vassal
person who has entered into a mutual obligation to a lord or monarch in the context of the feudal system in medieval Europe / From Wikipedia, the free encyclopedia
A vassal during the feudalism of medieval Europe, was someone who had shared duties with a lord. Usually the vassal provided soldiers to the lord. The lord used his army of soldiers from all of his vassals to protect those vassals. The lord also gave him the piece of land that he held as a fief. By analogy the term vassal is used also for similar systems in other feudal societies.