Demise is an Anglo-French legal term (from the Fr. demettre, Lat. dimittere, to send away) for a transfer of an estate, especially by lease. The word has an operative effect in a lease implying a covenant "for quiet enjoyment".

The phrase "demise of the crown" is used in English law to signify the immediate transfer of the sovereignty, with all its attributes and prerogatives, to the successor without any interregnum in accordance with the maxim "the king never dies". At common law the death of the sovereign eo facto dissolved Parliament, but this was abolished by the Representation of the People Act 1867, 51. Similarly the common law doctrine that a11 offices held under the crown determined at its demise has been negatived by the Demise of the Crown Act 1901 . "Demise" is thus often used loosely for death or decease.