Inquisition, in medieval and early modern history, a tribunal, or court, of the Roman Catholic Church for the discovery, punishment, and prevention of heresy and other religious offenses. There were three separate inquisitions: the medieval, Roman, and Spanish.

The Medieval Inquisitionbegan in 1229 after the heretical Albigenses of southern France had been crushed by a crusade against them. Pope Gregory IX sent the first inquisitors into Albigensian communities to complete the work of the crusade. (Some authorities give 1184 as the beginning date. In this year bishops and secular rulers were instructed by the Council of Verona to seek out heretics.) The Inquisition was later extended beyond France but was never established in Germany and England. The proceedings, often dominated by secular rulers, were usually secret, and torture was permitted. Even when a heretic recanted, he still had to pay various penalties. Unrepentant heretics faced confiscation of property. Sometimes, they were turned over to secular authorities, who often ordered death at the stake.

The Roman Inquisitionwas established by Pope Paul III in 1542 as the Holy Roman and Universal Inquisition of the Holy Office. It replaced the medieval Inquisition and became the supreme doctrinal tribunal for the whole Roman Catholic world. In 1908 the tribunal became the Congregation of the Holy Office, the final church court for cases on faith and morals. In 1965 Pope Paul VI changed its name to Congregation for the Doctrine of the Faith. Its procedures were liberalized, and its authority to act in secret was withdrawn.

The Spanish Inquisitionwas set up in 1478 by Ferdinand and Isabella with papal approval. It was instituted to check on the sincerity of converts from Judaism and Islam and later served also to suppress Protestantism. This Inquisition became notorious for cruelty under Tomás de Torquemada. It was often used for political purposes and frequently flouted the wishes of the popes. The ceremony used in condemning heretics was called auto-da-fé, Portuguese for “act of the faith.” The Inquisition finally came to an end in Spain in the early 1800's.