From Wikipedia

Secret Files Of The Inquisition
Episode Three

War On Ideas

Alonso de Hojeda, a Dominican from Seville, convinced Queen Isabel of the existence of Crypto-Judaism among Andalusian conversos during her stay in Seville between 1477 and 1478. A report, produced by Pedro González de Mendoza, Archbishop of Seville, and by the Segovian Dominican Tomás de Torquemada, corroborated this assertion.

The monarchs decided to introduce the Inquisition to Castile to discover and execute crypto-Jews, and requested the Pope's assent. "In 1498 the pope was still trying to ...gain acceptance for his own attitude towards the New Christians, which was generally more moderate than that of the Inquisition and the local rulers." Ferdinand pressured Sixtus IV by threatening to withdraw military support at a time when the Turks were threating Catholic Europe. On November 1, 1478, Pope Sixtus IV published the bill Exigit Sinceras Devotionis Affectus, through which the Inquisition was established in the Kingdom of Castile. The bill also gave the monarchs exclusive authority to name the inquisitors. The first two inquisitors, Miguel de Morillo and Juan de San Martín were not named, however, until two years later, on September 27, 1480 in Medina del Campo.

The first auto de fe was held in Seville on February 6, 1481: six people were burned alive. From there, the Inquisition grew rapidly in the Kingdom of Castile. By 1492, tribunals existed in eight Castilian cities: Ávila, Córdoba, Jaén, Medina del Campo, Segovia, Sigüenza, Toledo, and Valladolid.

Sixtus IV promulgated a new bull categorically prohibiting the Inquisition's extension to Aragon, affirming that,

many true and faithful Christians, because of the testimony of enemies, rivals, slaves and other low people—and still less appropriate—without tests of any kind, have been locked up in secular prisons, tortured and condemned like relapsed heretics, deprived of their goods and properties, and given over to the secular arm to be executed, at great danger to their souls, giving a pernicious example and causing scandal to many.

In 1483, Jews were expelled from all of Andalusia. Ferdinand pressured the Pope to promulgate a new bull on October 17, 1483, naming Tomás de Torquemada Inquisidor General of Aragón, Valencia and Catalonia. Torquemada established the procedures for the Inquistion. A new court would be announced with a thirty day grace period for confessions and the gathering of accusations by neighbors. Evidence that was used to identify a crypto-Jew included the absence of chimney smoke on Saturdays, a sign the family might secretly be honoring the Sabbath; or the buying of many vegetables before Passover; or the purchase of meat from a converted butcher. The court employed torture to extract a confession. Some of the cyrpto-Jews would be allowed to confess and do penance, while others were burned at the stake.

In 1484 Pope Innocent VIII attempted to allow appeals to Rome against the Inquisition, but Ferdinand in December 1484 and again in 1509 decreed death and confiscation for anyone trying to make use of such procedures without royal permission. With this, the Inquisition became the only institution that held authority across all the realms of the Spanish monarchy, and, in all of them, a useful mechanism at the service of the crown. However, the cities of Aragón continued resisting, and even saw revolt, as in Teruel from 1484 to 1485. However, the murder of Inquisidor Pedro Arbués in Zaragoza on September 15, 1485, caused public opinion to turn against the conversos and in favour of the Inquisition. In Aragón, the Inquisitorial courts were focused specifically on members of the powerful converso minority, ending their influence in the Aragonese administration.

The Inquisition was extremely active between 1480 and 1530. Different sources give different estimates of the number of trials and executions in this period; Henry Kamen estimates about 2,000 executed, based on the documentation of the Autos de Fé, the great majority being conversos of Jewish origin. He offers striking statistics: 91.6% of those judged in Valencia between 1484 and 1530 and 99.3% of those judged in Barcelona between 1484 and 1505 were of Jewish origin.