Getting accurate numbers is going to be problematic. Firstly, as you might expect, not all the records have survived. Secondly, a large number of those who were killed were never recorded in the official records of the Inquisition in the first place.
It should be made clear from the outset that claims of tens of millions of deaths as a result of the Inquisition - even over a period of several centuries - is simply mathematically untenable. For example, Spain had a population of about 7.5 million at the height of the Spanish Inquisition in the sixteenth century [Elliott, 1989, p223].
To place those numbers into further context, the Black Death killed an estimated 20 million people in Europe, or just under half the population, in the period from 1348 to 1352.
The first Inquisition was temporarily established in Languedoc (south of France) in 1184 by the Papal Bull Ad abolendam. This would lead directly to the Albigensian Crusade, which lasted from 1209 to 1244 and resulted in at least 200,000 Cathar deaths, and probably many more.
The Inquisition was permanently established in 1229, and run largely by the Dominican order until its abolition in the early 19th century (although part of the institution survived as part of the Roman Curia, and is known today as the Congregation for the Doctrine of the Faith).
Many of the excesses of the Albigensian Crusade are well known. For example, the massacre at Béziers, where the Cistercian Abbot and Papal Legate Arnaud Amalric allegedly told his men:
"Caedite eos. Novit enim Dominus qui sunt eius."
("Kill them all. God will know his own").
Amalric may, or may not, have spoken those exact words. However, he did confirm the broad details of the massacre (while effectively denying that he had any part in it) in a letter to the Pope in August 1209:
...while discussions were still going on with the barons about the
release of those in the city who were deemed to be Catholics, the
servants and other persons of low rank and unarmed attacked the city
without waiting for orders from their leaders. To our amazement,
crying "to arms, to arms!", within the space of two or three hours
they crossed the ditches and the walls and Béziers was taken. Our men
spared no one, irrespective of rank, sex or age, and put to the sword
almost 20,000 people. After this great slaughter the whole city was
despoiled and burnt...
Other contemporary writers put the death toll at up to sixty-thousand. Now, personally, I always find numbers like this in medieval documents a little suspect. They often seem unrealistically large and suspiciously round numbers. In this case, the true figure probably lies somewhere between the two extremes.
The massacre at Béziers serves to illustrate one major problem that will be faced if we try to estimate the death toll during the medieval Inquisition. Many of those killed simply do not appear in the official records of "the Inquisition". Of course, the massacre at Béziers was far from the only atrocity committed during the Albigensian Crusade. Malcolm Barber's brief overview The Albigensian Crusades: Wars Like Any Other? is well worth reading in this context.
Perhaps the best known manifestation of the Inquisition in the popular mind is the Spanish Inquisition, established in 1478. One of the earliest accounts came from a former Spanish secretary to the Inquisition named Juan Antonio Llorente (1756–1823). According to Llorente, nearly 32,000 “heretics” were burned at the stake during the Spanish Inquisition, and another 300,000 were put on trial and forced to do penance [Roth, 1964; p123].
Now, Llorente was an outspoken critic of the Spanish Inquisition and, although there are some who have argued that he actually underestimated the total number of deaths, there has been a tendency for modern historians to assume that his 32,000 figure is an exaggeration. The currently accepted view was set out by William Rubinstein in his 2004 book Genocide:
Juan Antonio Llorente (1756–1823), a fierce enemy of the Inquisition,
whose Critical History of the Inquisition of 1817–19 remains the most
famous early work attacking everything connected with it, estimated
the number of executions carried out during the whole of the period
that the Spanish Inquisition existed, from 1483 until its abolition by
Napoleon, at 31,912, with 291,450 “condemned to serve penances.” ...
Most recent historians regard even this figure as far too high.
[Rubinstein, 2004, p34]
So, if we limit the discussion to official executions during the Spanish Inquisition, experts today seem to place the total number in a range between about 3,000 and 10,000. A further 100,000 to 125,000 probably died in prison as a result of torture and maltreatment, but these went largely unrecorded in the records of the Inquisition. (The separate Inquisition in neighbouring Portugal resulted in fewer deaths) [Pérez, 2006, p173 and Rummel, 2009, p62]. Henry Kamen is one of the world's leading experts on the Spanish Inquisition. He concludes that:
We can in all probability accept the estimate, made on the basis of
available documentation, that a maximum of three thousand persons may
have suffered death during the entire history of the tribunal.
[Kamen, 2014, p253]
Although Kamen's figure is only concerned with executions. It does not include those who died in prison as a result of torture and maltreatment, and, as mentioned above, whose deaths would be largely absent from the official record.
One further point occurs to me. All these figures also omit the families of those accused by the Inquisition. In many cases they would have lost their sole means of support. Would their former friends and neighbours have provided assistance, or would they have been afraid of guilt-by-association? Based on what we have seen elsewhere over the years - not least in the twentieth century - it seems likely that it would have been the latter. If that was the case, then many would certainly have succumbed to the diseases associated with poverty who would not otherwise have done so. Should their deaths also be added to the total? If so, how would we arrive at an even approximately accurate figure?
If the term "Inquisition" is used in its broader sense, to include all Roman Catholic activities against non-Catholics, then, as we might expect, the death-toll increases dramatically. In his 2006 paper, Estimates of the Number Killed by the Papacy in the Middle Ages and Later, David Plaisted attempts to arrive at an estimate including figures for deaths resulting from forms of torture and killing that did not involve a formal trial, religious wars, and other forms of Catholic violence enacted against Protestants and other non-Catholics. This text also includes some useful links to further source material.
If the discussion includes this wider context, then it certainly is possible to talk about death tolls potentially measured in the millions.
A different perspective on the history of the Inquisition can be seen in this article in the Catholic Encyclopedia.
- Barber, Malcolm: The Albigensian Crusades: Wars Like Any Other?,
- Kamen, Henry: The Spanish Inquisition: A Historical Revision,
- Elliott, John Huxtable: Spain and Its World, 1500–1700, Yale,
- Pérez, Joseph: The Spanish Inquisition: A History, Profile
- Peters, Edward: Inquisition, University of California, 1989
- Plaisted, David: Estimates of the Number Killed by the Papacy in the
Middle Ages and Later, University of North Carolina, 2006
- Roth, Cecil: The Spanish Inquisition, Norton, 1964
- Rubinstein, William D: Genocide, Routledge, 2004
- Rummel, R.J: Death by Government, Transaction Publishers, 2009