Men harvesting wheat with reaping-hooks as part of their feudal duties, 1310 A.D. (C.E.)

During the Middle Ages, a king, lords, vassals (lesser lords like knights), and serfs relied on one another, and worked together to create a system of political and economic protections. A king could not protect and control all of his land, so he rented it to vassals. The vassals offered military service in return, and could supply food to the king if necessary. Serfs were the backbone of the manorial system, as they raised or produced nearly everything they and their lord needed in daily life. Everyone in the feudal system had a job to do, and therefore, they all played important roles in the survival of medieval kingdoms against invading barbarians.