The Inquisition, by definition, had no jurisdiction over anyone other than Christians. Any Jews they persecuted were individuals who had converted to Catholicism, normally referred to as "New Christians" or conversos, and who were still engaging in "Judaicizing," a term that was very inclusive and included washing too often.

The request for establishment of an Inquisition that was sent to Rome in 1478 was signed by both Ferdinand and Isabella, as co-monarchs, and Ferdinand is credited with the responsibility for spreading it beyond Castille itself.

The expulsion of the Jews and the Moors in 1492 was intended to make Spain a totally Christian nation, and to free the Spanish from the influence of non-Catholics.