An entail, or fee tail, is a legal device originating in English common law designed to prevent the alienation of family estates. By restricting the inheritance of land to a specific class of heirs—most commonly 'heirs male of the body'—the settlor ensured that the property remained intact and within the direct patrilineal descent, rather than being subdivided among daughters or sold to satisfy personal debts. This created a life interest for the current occupant, who acted as a steward rather than an absolute owner, thereby preserving the territorial basis of the nobility's political power and social status across generations.
The development of the entail reached its zenith with the 'Strict Settlement' in the 17th century, which utilized trustees to protect the interests of unborn heirs. This mechanism effectively locked estates into a cycle of succession that was difficult to break without the consensus of both the life tenant and the heir apparent through a process known as 'barring the entail' (via legal fictions like common recovery). While it provided financial stability and protected the family seat, it often left younger sons and daughters dependent on modest annuities, as the bulk of the wealth was inextricably tied to the landed title.