“I have caused great calamities and depopulated towns, lands, provinces and kingdoms,” Isabella wrote her ambassador in Rome, who was to defend the Castilian Inquisition by telling the pope that she had done all “for the sake of Christ and His Holy Mother.” Any such mono-causal explanation for the policies of the Reyes Católicos was instinctively distrusted by Francisco Guicciardini, a canny Florentine, who saw enough of Ferdinand when serving as ambassador to the Castilian court to observe with cynical admiration: “This is what made the enterprises of his Catholic Majesty so glorious – they were always undertaken for his own security or power, but often they would appear to be done either to strengthen the Christian faith or to defend the church.”

Whatever the mixture of motives, few foresaw before they came to power that Ferdinand, together with Isabella, would completely destroy the last of an ancient Iberian tradition of convivencia, which had permitted creeds to coexist. Much of the survival of the remnants of this toleration depended upon prompt action by corregidores. They were often all that protected the separated communities from the hostility of the clergy, the brutality of the populace, and the envy of the urban oligarchy. We trace during the new reign the gradual, often imperceptible, shift of the royal official from protector of Jews to their persecutor, and from adjudicator of Muslim rights to their foe.