History abounds in "private inquisitors" who took the lives of heretics from time to time in an excess of religious zeal, but no other organization for religious persecution ever equaled the Spanish Inquisition in intensity, scope, or efficiency of operation. In 1478 Pope Sixtus IV issued the fatal Bull empowering the Spanish sovereigns to set up tribunals to extirpate heresy within their realms, and from then until its abolishment in 1834 the Inquisition...