The enclosure acts ending the system of open field farming began in the medieval period and culminated in the late 18th and early 19th centuries. By the mid-nineteenth century, the older system of open field farming had almost disappeared. These acts resulted in a revolution in agricultural practice and are widely studied by historians.
The first reason for them was the increased profitability of sheep farming, resulting in the need for enclosed pastures for large scale sheep herds. This was the main reason for enclosures in the 16th and 17th centuries – that sheep grazing was more profitable than tenant farming.
In the late 18th century, new agricultural techniques such as crop rotation, fertilization, and new ploughs required larger more open fields rather than small strips to be effective.
Finally, enclosures often were extremely profitable for landlords.