A liberty was an English and Irish geographic unit originating in the Middle Ages, traditionally defined as an area in which regalian right was revoked and where the land was held by a mesne lord (i.e., an area in which rights reserved to the king had been devolved into private hands). It later became a unit of local government administration.
Liberties were areas of widely variable extent which were independent of the usual system of hundreds and boroughs for a number of different reasons, usually to do with peculiarities of tenure. Because of their tenurial rather than geographical origin, the areas covered by liberties could either be widely scattered across a county or limited to an area smaller than a single parish: an example of the former is Fordington Liberty, and of the latter, the Liberty of Waybayouse, both in Dorset.