The Spanish Inquisition investigated and prosecuted suspected heretics, conversos, and others. Methods included prolonged imprisonment, torture (strappado, waterboarding-like methods, the rack), and public autos-da-fé in which the condemned were burned or otherwise executed. The institution operated under royal authority for more than three centuries.
The Inquisition was progressively restricted and finally abolished in Spain in 1834 during the liberal reforms of the 19th century. Its records have since become a major historical source, and the institution remains a byword for religious intolerance and judicial cruelty.