DUKE OF  EXETER'S DAUGHTER, a nickname applied to a 15th-century instrument of torture resembling the rack (q.v.) . Blackstone says (Commentaries, ii. sec . 326): " The trial by rack is utterly unknown to the law of England, though once when the dukes of Exeter and Suffolk, and other ministers of Henry VI., had laid adesign to introduce the civil (i.e . Roman) law into the kingdom as the rule of government, for a beginning thereof they erected a rack for torture, which.was called in derision the duke of Exeter's daughter, and still remains in the Tower of London, where it was used as an engine of state, not of law, more than once in Queen Elizabeth's reign .