Feudal serf is a term used to describe the lowest class of peasant in the feudal system. An ESNE was a medieval English serf who was bound to a lord's service and could be bought and sold with the land. A PEON was a person who was bound to a lord's service and was not allowed to leave the estate without permission. Both ESNE and PEON were expected to provide labor and services to their lord in exchange for protection and the use of land.