The exchange between lords and vassals was the central aspect of feudalism. The lords gave fiefs to their vassals. This meant that the vassal got an area of land. He got the right to its produce and the right to the labor of its inhabitants. He also got the right to dispense justice in his fief. In return, the vassal promised certain things to the lord. He promised to provide military support when called upon. He promised to give a percent of the produce of his lands to the lord. He promised to be loyal to his lord. This exchange of rights and responsibilities was the basis of feudalism.