Feudalism was a dominant social and economic system in medieval Europe, characterized by the exchange of land for military service. Lords owned large estates and granted portions of their land, known as fiefs, to vassals in return for loyalty and protection. This hierarchical structure created a network of obligations and relationships among different classes, including nobles, knights, and peasants. At the bottom of the feudal hierarchy were the serfs, who worked the land and provided food for the lords and vassals. In exchange, they received protection and a place to live. This system shaped the political landscape of Europe for centuries, influencing governance and social relations.