The social structure of feudalism in medieval Europe was hierarchical and divided primarily into three classes: the nobility, the clergy, and the peasantry. At the top were monarchs or kings, who granted land to noble lords in exchange for military service. These lords controlled vast estates, which were worked by serfs or peasants, who were bound to the land and provided agricultural labor. The clergy held spiritual authority and often owned land as well. This system defined the political, economic, and social dynamics of medieval Europe, establishing obligations and loyalties through land ownership and service.