Historically, enclosure refers to the privatization of common grazing lands beginning in 15th Century England, which impoverished many peasants. Today it is used to describe the conversion of a commons into private property. Enclosure entails not just the privatization of a resource, but also the introduction of money and market exchange as the prevailing principles for managing that resource. Enclosure often shifts ownership and control from the community at large to private companies. This in turn changes the management and character of the resource because the market has very different standards of accountability and transparency than a commons. Because of its compulsion to extract maximum short-term rents and externalize costs, market enclosure often results in the “tragedy of the market.”
Enclosure is the process which was used to end some traditional rights, such as mowing meadows for hay, or grazing livestock on land which is owned by another person, or a group of people. In England and Wales the term is also used for the process that ended the ancient system of arable farming in open fields. Under enclosure, such land is fenced (enclosed) and deeded or entitled to one or more owners. By the 20th century, unenclosed commons had become largely restricted to rough pasture in mountainous areas and in relatively small parts of the lowlands.
"Enclosure" is the modern spelling, while "inclosure" is an older spelling still used in the United Kingdom in legal documents and place names.
The process of enclosure has sometimes been accompanied by force, resistance, and bloodshed, and remains among the most controversial areas of agricultural and economic history in England. Marxist and neo-Marxist historians argue that rich landowners used their control of state processes to appropriate public land for their private benefit. This created a landless working class that provided the labour required in the new industries developing in the north of England. For example: "In agriculture the years between 1760 and 1820 are the years of wholesale enclosure in which, in village after village, common rights are lost". "Enclosure (when all the sophistications are allowed for) was a plain enough case of class robbery".
W A Armstrong argued that this is perhaps an oversimplification, that the better-off members of the European peasantry encouraged and participated actively in enclosure, seeking to end the perpetual poverty of subsistence farming. "We should be careful not to ascribe to (enclosure) developments that were the consequence of a much broader and more complex process of historical change".