The Spanish Inquisition remains one of the most infamous institutions in European history. It has the reputation of ruthlessly suppressing dissent, hunting down Protestants, and freely resorting to brutal torture. Some elements of this “Black Legend” are exaggerated; others are rooted in fact. The Spanish Inquisition was an institution that was deeply tied up with the Spanish experience of the Reconquista. Established before the Reformation, its primary targets in its initial, and most active, decades were converted Jews.

In this chapter we document the rise of the Spanish Inquisition and relate it to the conditional toleration equilibrium that characterized medieval Europe. At the same time, though a product of the general medieval equilibrium we have described, the Spanish Inquisition was also a uniquely Iberian institution. First, it had its origins in a late medieval Spain that was much more religiously diverse than any other part of Europe. Second, we will emphasize that the key to the identity of the Iberian rulers and their claim to legitimacy was their status as crusader kingdoms reclaiming lands from infidel Muslims.

These two factors interacted with one another. On the one hand, the religious diversity of lands conquered by the monarchs of Castile and Aragon in the twelfth and thirteenth centuries made enforcing religious conformity impossible. During the Reconquista itself, largely pragmatic attitudes toward non-Christians held sway. As the Christianmonarchs absorbed new territories, they allowed Jews andMuslims to continue their religious practices. On the other hand, the most important source of royal legitimacy and the means through which rulers could assert themselves over the nobility or independent cities was by stressing their identity as crusaders and as Christian monarchs.

These competing forces can be seen in the decision to establish a “royal” inquisition independent of the papacy in 1478. Opposition to heresy was a way the new rulers of a unified Castile and Aragon legitimated their rule and elevated themselves over their rivals. But, as with the persecution of Protestants in mid-sixteenth-century France, establishing an institution capable of investigating, imprisoning, and prosecuting large numbers of people created an “engine of repression.” Unlike in England or France, however, the Spanish monarchy was successful in suppressing religious differences by the early seventeenth century: Jews and Muslims were expelled or compelled to abandon their old faith and Protestantism was eliminated. The Iberian peninsula was, as a result, truly Catholic for the first time since Visigothic times.