What did Queen Isabella and King Ferdinand do in order to make Spain purely Catholic?

The Catholic Monarchs (Spanish: Reyes Católicos) is the joint title used in history for Queen Isabella I of Castile and King Ferdinand II of Aragon ... The court of Ferdinand and

Ferdinand and Isabella chose Catholicism to unite Spain and in 1478 asked permission of the pope to begin the Spanish Inquisition to purify the people of Spain. They began by driving out Jews, Protestants and other non-believers. In 1483 Tomas de Torquemada became the inquisitor - general for most of Spain.