In the manorialist system of land ownership which existed across much of Europe during the feudal era, the demesne was a section of land set aside for the exclusive use of the lord of the manor. By contrast, so-called alienated lands were given out as freeholds by the lord. The lord could use the demesne however he saw fit, and the uses for this land shifted radically throughout the feudal era, depending on the condition of the economy, the demand for various consumer goods, and regional differences.
This term literally means “domain,” and it sometimes appears in old books as an archaic spelling for “domain.” It comes from the Old French demeine, derived from the Latin dominicus, “belonging to the master.”
The demesne did not necessarily have to be contiguous with the manor house, although it often was. It was common for lords to select the finest lands for themselves, and there was sometimes a conflict between the lord's demesne and the glebe lands belonging to the Church, since the Church was also eager to get its hands on the best land possible. Many such conflicts had to be resolved by the Monarch, with Monarchs considering the balance between rewarding loyal followers with land and placating the immensely powerful medieval Church.
In some regions, the lord worked the demesne himself, but it was more common for the land to be worked by serfs, who labored for free in return for housing and small plots of land on which they could grow their own food. This slave-like relationship slowly began to evolve, with the lord instead renting out lands to serfs and peasants for them to work. Over time, many of these rents turned into hereditary leases, and although the residents did not own the land in freehold, they essentially controlled it and acted like landlords, looking out for the well-being of the land and making critical decisions about land use.
After the medieval era, this type of land ownership began to be phased out, although some examples of former manorial estates do exist. For example, several small villages and settlements in England are still owned by a single family which leases homes to residents in a remnant of the feudal system. In modern times, feudalism has come to be viewed as an extremely unjust system, especially in the United States, where many people have a great deal of faith in upward mobility, something which was not available to most people in the feudal era.