The Tribunal of the Holy Office of the Inquisition, commonly known as the Spanish Inquisition, was a tribunal established in 1478 by Catholic Monarchs Ferdinand II of Aragon and Isabella I of Castile. It was intended to maintain Catholic orthodoxy in their kingdoms, and to replace the medieval inquisition which was under papal control. The Inquisition worked in large part to ensure the orthodoxy of recent converts, especially those Jews, Muslims and others coerced on pain of death to adopt the Christian religion. The first Inquisitor General was Tomás de Torquemada, who in 1491 was persuaded by Rodrigo Borgia to arrest a number of Spanish Assassins. The Inquisitors were known for their unnecessary amount of violence towards those who were not of the same religion.