In English law, heirs of the body is the principle that certain types of property pass to a descendant of the original holder, recipient or grantee according to a fixed order of kinship.
[1] Upon the death of the grantee, a designated inheritance such as a parcel of land, a peerage, or a monarchy, passes automatically to that living, legitimate, natural descendant of the grantee who is most senior in descent according to primogeniture, males being preferred, however, over their sisters regardless of relative age; and thereafter the property continues to pass to subsequent descendants of the grantee, according to the same formula, upon the death of each subsequent heir.
Baronies created by writ of summons to Parliament usually descend to heirs of the body of the grantee, and may thus be inherited by females.
In property law, a conveyance by the owner O "To A and heirs of the body", without more, creates a fee tail for the grantee (A) with a reversion in the grantor (O) should the natural, lawful descendants of the grantee all die out.
Thus property settled upon someone and the heirs of their body—whether male, female, or generally—will pass to children, grandchildren and so on, but not to nephews of the grantee, his or her sisters, uncles and their descendants.