The Spanish Inquisition lasted from 1478 to 1834 and was started by the monarchs Ferdinand II and Isabella. The marriage of Ferdinand II of Aragon to Isabella of Castile united two kingdoms on the Iberian pennisula. The Spanish Inquisition was set apart from the long running and contemporary papal inquisitions through a special papal bull issued from Pope Sixtus IV to the Spanish monarchy. The crown was able to gain political control over the appointment of inquisitors in Castile which, until then, had managed to avoid the implementation of inquisitions by the church.
The priviledged commission granted to the Spanish Inquisition afforded considerable magisterial control to the Spanish Monarchy and allowed it to focus on the eradication of Jewish and Muslim influence in Spain. Prior to the issuance of the bull, the church had a focus on the reconciliation of heretics back to the church. Under the Spanish Crown, however, judiazing heretics were the subject of particularly enthusiastic prosecution. Under the guise of spiritual mandate, Jews were compelled to leave behind their wealth and exit Spain or convert to Christianity. But all would not bode well for the conversos.
Over time, the conversos and their decendants would be suspected of secret Judiazing and the practice of Mosaic law. A kind of circuit court of inquisitors was instituted early in the Inquisition whereupon a select Grand Inquisitor would oversee the conduct of Inquisitions throughout the realm on behalf of the Crown.
A codified system of procedures and functionaries was put in place for the conduct of inquisitions. Suspected heretics were always presumed guilty until they could prove their innocence. An inquisition was conducted in a way so as to elicit a confession since this was regarded as the best form of evidence of guilt. Torture was instituted and performed when stubborn heretics failed to confess to the satisfaction of the inquisitors.
The variety of torture techniques included hanging the defendant by his wrists which were tied behind his back (the garrucha); stretching the defendant on the rack (the potro); or pouring water down the nose and throat of the defendant to simulate drowning (the toca). These techniques were conducted in order to produce a satisfactory confession.
At the conclusion of the inquisition, the guilty defendant was “relaxed” to the constable for punishment or execution. In this system, there was no external authority such as the pope to contradict the will of the Crown in the roundup and prosecution of suspected heretics.
Of special interest is the toca. This seems to be a form of what we now call “waterboarding”. It is generally agreed that when the Inquisitors performed it, it was regarded as a form of torture. The contemporary practice is defined as “enhanced interrogation”.
It was the Spain of this Inquisition period that set sail for the Americas in search of wealth and for natives to convert to Christianity. Unfortunately for the native people of the Americas, these visitors had a frothy zeal for heavy metals and Christ.
Reference: Lu Ann Homza, The Spanish Inquisition, 1474-1614, 2006, Hackett Publishing Company, ISBN 0-87220-794-3.
Lamentations on Chemistry 
I have talked to some proselyting Catholics in Mexico. According to what they have been taught the Spanish Inquisition was made up by the Protestants and published in encyclopedias to make the Catholic Church look bad. Almost sounds like the skin heads claiming the holocaust did not exist.
It is my understanding that the inquisitors kept very detailed records of their activities. Ferdinand II and Isabella began their own inquisition and secured rights to conduct inquisitions independant of Rome. They and their successors were particularly concerned about the rise of the protestant reformation … after, of course, they had routed out the Jews and Muslims from their realm.
It’s not that the Spanish Inquisition is fictional, it’s that it has been grossly exaggerated. To put it into perspective, 3000-4000 people were executed by the Spanish Inquisition in its 400 year history. King Henry VIII alone executed 72,000 people during his 38-year rule.
The Black Legend surrounding the Spanish Inquisition demonizes Hispanic peoples to this day and is a tragedy, as well as the Spanish Inquisition itself.