I've heard it referred to as the 'black legend' or something like that which implied few people were tortured or killed by the Spanish Inquistion which seems to have been put in place after Spain finished conquering the Moors in 1492. In popular imagination the organization seems to have killed and/or tortured 100,000s or millions of people, forcibly converted people. My guess is if really was so brutal we'd find mass graves.
What evidence do we have?
To clear one thing, the "Black Legend" doesn't deal with the Spanish Inquisition (i bet you weren't expecting that). The Black Legend was the propaganda put forth by non-Spanish powers that said the Spanish were uniquely brutal in their conquest. This was not true. The other colonial powers were brutal as well.
Hi there, while you await an answer from an expert you may be interested in these other threads on the Spanish Inquisition and inquisitions in general.
AMA - Medieval Witchcraft, Heresy, and Inquisition -- posted 9 months ago, 112 comments
Why is the Spanish Inquisition associated with torture and violent interrogations? -- posted 10 months ago, 9 comments
Was the Inquisition as bad as it's made out to be? -- posted 1 year ago, 14 comments
If you see something of note in those threads, feel free to post follow-up questions here, and tag the user in your comment. Also, I'll go ahead and page /u/idjet, who is a flaired user in heresy and inquisition.
I'm sure a proper historian will come along in time, but in the mean time I can give you some numbers about people sentenced to death by the Spanish Inquisition in the Low Countries (Netherlands, Belgium and Luxembourg, some of which were also at the time densely populated and urban areas; at least in contrast to other areas in Europe). The total number from inception until 1566 is estimated at 1300 deaths by Alistair Duke ('Reformation and Revolt'). The enemies of Catholicism made the number much higher for propaganda purposes. Nevertheless, the author of the book who referred to Duke (Anton van der Lem in 'De Opstand in de Nederlanden 1568-1648') calls this a very high number when contrasted with other Spanish areas. In fact, he writes that in first centuries of its existence, only 200 people had been sentenced to death. Note also that these are sentences, so it is unclear if they were actually carried out. The number of sentences in the Low Countries were so high because of the protestant revolt, whereas in Catholic areas the Inquisition may even have been welcomed because it allowed people who had been accused to demonstrate what a good Catholic they were.
Just a followup question. Was there an appreciable difference between the Spanish Inquisition and the Inquisition in Rome? My basis of knowledge for the Spanish Inquisition is Monty Python (i.e., nothing), but I've learned a fair bit more about Rome by reading about Galileo. In those cases, it seemed there were quite a few accusations against Galileo that were responded to professionally and fairly and the cases were then closed, finding the accusations unsubstantiated. Certainly a far cry removed from the traditional story.