In trial by ordeal the accused was subjected to some harsh test—holding hot iron, being cast into a pool of water—with guilt or innocence decided according to the outcome. Although a strange and alien custom, trial by ordeal has been an important legal procedure in many regions and periods. Robert Bartlett here examines the workings of trial by ordeal from the time it first appeared in the barbarian law codes, tracing its use by Christian societies to its last days as a test of withcraft in Europe and America. He discusses recent theories about the operation and decline of the practice, shedding new light on both the ordeal as a working institution and the pressure for its abolition.