The Inquisition in Spain
Ferdinand and Isabella establish a tribunal that judges not Jews but converts — secret 'Judaisers'; denunciations, torture and the fires of the auto-da-fé begin.
After the massacres of 5151 and the preaching campaigns of the early fifteenth century, tens of thousands of conversos lived in Spain. Many rose high — royal officials, bishops, married into noble houses. That enraged the 'old Christians,' who began to speak of purity of blood and of converts who only pretended.
In 5239 Pope Sixtus IV, at the request of Ferdinand of Aragon and Isabella of Castile, permitted a tribunal in Spain answerable to the crown rather than to Rome. The first court opened in Seville in 5241 (Tishrei, September 1480), and in that same year, on 8 Adar (February 1481), came the first auto-da-fé — the 'act of faith,' a public reading of sentences and burning of the condemned. Within a few years the Dominican Tomás de Torquemada became Inquisitor General.
The structure matters: the Inquisition had no authority over Jews. Its victims were the baptised and their children, subject to the Church as Christians. The charge was Judaising: a neighbour reported that no fire was lit on Saturday, that linen was changed on Friday evening, that pork was refused. Accusers' names were withheld, confession was extracted by torture, and the condemned man's property went to the treasury.
Within a decade thousands burned in Seville, Cordoba and Zaragoza. And an argument matured that would justify what came next: while Jews live nearby, the conversos will never become true Christians.