The Inquisition was a permanent institution in the Catholic Church charged with exposing, punishing and eradicating religious heresies. It derived its name from the Latin verb inquiro (inquire into). Heresies (from the Latin haeresis, sect, school of belief) were a problem throughout the history of the church. In the early centuries there were the Arians and Manicheans; in the Middle Ages there were the Cathari and Waldenses; and in the Renaissance there were the Hussites, Lutherans, Calvinists, and Rosicrucians. Because witchcraft became to be viewed as a heresy, it too fell within the purview of the Inquisition.

Efforts to suppress heresies were initially ad hoc, but abuses by various local Inquisitions led to reform and regulation by Rome so that a permanent structure came into being to deal with the problem. Beginning in the 12th century, Church Councils required secular rulers to prosecute heretics. In 1231, Pope Gregory IX published a decree which called for life imprisonment with salutary penance for the heretic who had confessed and repented and capital punishment for those who persisted. The secular authorities were to carry out the execution. Pope Gregory relieved the bishops and archbishops of the obligation of conducting Inquisitorial proceedings, and made this the duty of the Dominican Order, though many inquisitors were members of other orders such as the Franciscans, or came from the secular clergy. By the end of the decade the Inquisition had become a general institution in all lands under the overview of the Pope, and by the end of the 13th century the Inquisition in each region had evolved a bureaucracy to help in carrying out its function.

At the end of the 15th century, under Ferdinand and Isabel, the Spanish inquisition became independent of Rome. By its dealings with converted Moslems and Jews, the Spanish Inquisition, with its notorious autos-da-fés, has become notorious. In northern Europe however, the Inquisition was considerably more benign: in England it was never instituted, and in the Scandinavian countries it had hardly any impact.

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Manuel de l'inquisiteur

BERNARDUS Guidonis, Bishop of Lodève, 1261 or 62-1331
Manuel de l'inquisiteur. Édité et traduit par G. Mollat.
Paris: Champion, 1926-27.

A complete history of the Inquisition in Portugal, Spain...

A Complete history of the Inquisition in Portugal, Spain, Italy, the East and West-Indies: in all its branches, from the origin of it in the year 1163 ...
Westminster : Printed and sold by O. Payne, 1736

With a second title page from the firs edition of 1734. Illustrated with copper engraved plates depicting scenes of torture

Three letters concerning the present state of Italy...

BURNET, Gilbert
Three letters concerning the present state of Italy, written in the year 1687 ...
London : [s.n.] 1688

Tractatus de Officio Sanctissimoe Inquisitionis

CARENA, Cesare
Tractatus de Officio Sanctissimœ Inquisitionis : et modo procedendi in causis fidei : in tres partes divisus ...
Cremonœ: apud Io. Baptistam Belpierum, 1655.
A history of persecution...

A History of persecution in four parts ...
London: Printed for J. Gray, 1736
Manual des inquisiteurs

EYMERIC, Nicholas. (1320-1399).
Manual des inquisiteurs; a l’usage des inquisitions d’Espagne et de Portugal ...
Lisbon: 1762
History of the inquisition

History of the inquisition
London : J. Gray, 1731
Praxis iudicaria inquisitorum...

LOCATI, Umberto
Praxis iudicaria inquisitorum ...
Venice: Apud Damionum Zonarum, 1583
De Equuleo liber posthumous

MAGII, Hieronymi Anglarensis
De Equuleo liber posthumous…
Amsterdam: Sebastian Combi & Joannis Lanou, 1664
De Origine et progressu offici...

PARAMO, Ludovicus de
De Origine et progressu offici Sanctae Inquisitionis ...
Madrid: Typographia Regia, 1598
A short and true account of the  Inquisition

PIAZZA, Hieronymus Batholomew
A Short and true account of the Inquisition and its proceeding, as it is practised in Italy, set forth in some particular cases
London: William Bowyer, 1722

The author purported to be "formely a Lector of Philosophy and Divinity, and one of the Delegate Judges of that Court, and now by the Grace of God, a Convert to the Church of England." Detailed first-hand atrocity stories, and an account of Papal censoring of books. With extracts from a book of legends of the Roman Catholic Saints.