The Tribunal of the Holy Office of the Inquisition (Spanish: Tribunal del Santo Oficio de la Inquisición), commonly known as the Spanish Inquisition (Inquisición española), was 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. It became the most substantive of the three different manifestations of the wider Christian Inquisition along with the Roman Inquisition and Portuguese Inquisition. The "Spanish Inquisition" may be defined broadly, operating "in Spain and in all Spanish colonies and territories, which included the Canary Islands, the Spanish Netherlands, the Kingdom of Naples, and all Spanish possessions in North, Central, and South America."
The Inquisition was originally intended primarily to ensure the orthodoxy of those who converted from Judaism and Islam. The regulation of the faith of the newly converted was intensified after the royal decrees issued in 1492 and 1502 ordering Jews and Muslims to convert or leave Spain. The Inquisition was not definitively abolished until 1834, during the reign of Isabella II, after a period of declining influence in the preceding century.
The Spanish Inquisition is often stated in popular literature and history as an example of Catholic intolerance and repression. Modern historians have tended to question earlier accounts concerning the severity of the Inquisition. Henry Kamen asserts that the 'myth' of the all-powerful, torture-mad inquisition is largely an invention of nineteenth century Protestant authors with an agenda to discredit the Papacy. Although records are incomplete, about 150,000 persons were charged with crimes by the Inquisition and about 3,000 were executed.