A writ of habeas corpus is a writ that requires a person under arrest to be brought before a judge or into court. The principle of habeas corpus ensures that a prisoner can be released from unlawful detentionâthat is, detention lacking sufficient cause or evidence. The remedy can be sought by the prisoner or by another coming to the prisoner's aid. This right originated in the English legal system, and is now available in many nations. It has historically been an important legal instrument safeguarding individual freedom against arbitrary state action. It has been extended to non-police authorities, as in the 1898 Queen's Bench case of Ex Parte Daisy Hopkins, which has successfully been utilized more recently in India to liberate a woman from a madrasa.