Honorius lumps together everyone who worked the land, but in fact there were many levels of peasants ranging from outright slaves to free but poor peasants to very rich farmers. The number of slaves who worked the land declined steadily in the High Middle Ages, and those who remained tended to live with wealthier peasant families or with lords. Most rural people in western Europe during this period were serfs rather than slaves, though the distinction between slave and serf was not always clear. Both lacked freedom and both were subject to the will of one person, the manorial lord. Serfs remained bound to the land when their lords died, but unlike slaves they could not be bought and sold outright.

Most serfs worked small plots of land; in addition, all serfs were required to provide a certain number of days of labor a week — more in planting and harvest seasons — on a lord’s land. Serfs were also often obliged to pay fees on common occurrences, such as marriage or the inheritance of land from one generation to the next.

Serfdom was a hereditary condition. A person born a serf was likely to die a serf, though many serfs did secure their freedom. As money became more widely available and widely used, some serfs bought their freedom. Some gained it when manorial lords organized groups of villagers to cut down forests or fill in swamps and marshes to make more land available for farming. A serf could clear a patch of fen or forestland, make it productive, and, through prudent saving, buy more land and eventually purchase freedom. Serfs who migrated longer distances, such as German peasants who moved eastward into Slavic lands, were often granted a reduction in labor services as a reward. Thus both internal and external frontier lands in the High Middle Ages provided some opportunities for upward mobility.