During the Middle Ages inquisition meant an enquiry, undertaken ad hoc by papally appointed inquisitors. While at the time the Latin term inquisitio could be applied to enquiries of any kind, historians have come reserve the term to describe the task of detecting, prosecuting, and punishing heretics and their sympathizers by papally appointed judges. This procedure flourished mostly in the thirteenth and fourteenth centuries; in the fifteenth century many aspects of inquisitorial procedure were adopted by bishops to deal with heresy in their dioceses, especially in England and Bohemia.

During the early modern period this office became the basis for the creation of several national institutions, generally dedicated to the prosecution of religious dissent but whose main interests and concerns varied according to local demands. While the medieval and early modern inquisitions share many characteristics, notably of...