In medieval and Early Modern England, a deer park was an enclosed area containing deer. It was bounded by a ditch and bank with a wooden park pale on top of the bank, or by a stone or brick wall. The ditch was on the inside increasing the effective height. Some parks had deer "leaps", where there was an external ramp and the inner ditch was constructed on a grander scale, thus allowing deer to enter the park but preventing them from leaving.
Some deer parks were established in the Anglo-Saxon era and are mentioned in Anglo-Saxon Charters; these were often called hays.
After the Norman conquest of England in 1066 William the Conqueror seized existing game reserves. Deer parks flourished and proliferated under the Normans, forming a forerunner of the deer parks that became popular among England's landed gentry. The Domesday Book of 1086 records thirty-six of them.
Initially the Norman kings maintained an exclusive right to keep and hunt deer and established forest law for this purpose. In due course they also allowed members of the nobility and senior clergy to maintain deer parks. At their peak at the turn of the 14th century, deer parks may have covered 2% of the land area of England.
James I was an enthusiast for hunting but it became less fashionable and popular after the Civil War. The number of deer parks then declined, contemporary books documenting other more profitable uses for such an estate. During the 18th century many deer parks were landscaped, where deer then became optional within larger country parks, several of which were created or enlarged from wealth from trade and colonization in the British Empire. These later mostly gave way to profitable agriculture dependent on crop prices, with large parts of the workforce having been attracted elsewhere following increasing industrialization. This created pressure to sell off parts or divide such estates while rural population growth pushed up poor law rates (particularly outdoor relief and the Labour Rate) and urban poverty led to the introduction of lump sum capital taxation such as inheritance tax and a shift in power away from the .