The Spanish and Portuguese Inquisitions that began in the late 15th and 16th centuries and lasted well into the 19th century were rooted in the papal inquisitions of the earlier medieval period. The purpose of these tribunals was to arrest and punish persons who deviated from accepted beliefs and practices of the Church. These courts, in turn, were ultimately linked to the religious panels established as early as the reigns of the Roman Emperors Theodosius in the West and Justinian in the East.
The institution, as it is now known, began in the thirteenth century when it was set up to combat the heretical sect of the Albigenses. The Albigenses or Cathars embraced Gnostic beliefs that held the God of the New Testament was distinct from the God of the Old Testament. One was opposed to the other. A military crusade was launched against the Albigenses, but the movement went underground. Out of concern for this group, the tribunal was established in several cities in southern France.
The Papacy entrusted the Inquisition to the mendicant orders of Dominicans and Franciscan friars. The mendicant orders were bound by a vow of poverty and an ascetic lifestyle. Local bishops had the authority to investigate heresy, but the mendicant orders provided a more extensive organization. The medieval Inquisition had the power to punish Jews who aided Jewish converts to return to Judaism. The Inquisition also had the authority to order testimony by Jews against lapsed converts. In its early years, however, little attention was paid to Jews other than an occasional action focused on banning or burning certain Jewish books that had been deemed heretical or offensive to Christianity.
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 In 385 CE, the Christian Emperor Maximus tortured and executed the heretic Priscillian and some of his followers. Cecil Roth, The Spanish Inquisition (New York: W.W. Norton and Company, 1964), 35. See also Jean Plaidy, The Spanish Inquisition: Its Rise, Growth, and End (New York: Barnes and Nobles, 1994), 18. The Inquisition also targeted Waldesians. The beliefs of the Waldesians are difficult to ascertain but appear to have reflected elements of later Protestant reformers. Joseph Perez, The Spanish Inquisition: A History (London: Profile Books, 2006), 101.
 The threat of the Albigensian sect was met by severe Inquisitional scrutiny as the historian Cecil Roth noted: “The heresy was apparently stamped out by the so-called Albigensian Crusades from 1209 to 1244, but no sooner had these wars ended in victory for the orthodox party than a fresh problem presented itself. It was discovered that the detested heresy had not been eradicated, but only driven underground, and the idea was conceived that in order to detect and convict heretics it was necessary to employ persons specially qualified for the purpose.” Cecil Roth, The Spanish Inquisition (New York: W.W. Norton and Company, 1964), 36.
 The auto da fé (Portuguese) or auto de fé (Spanish) referred to the public sentencing of those convicted of heresy. The term itself means act of faith. I have chosen to use the terms interchangeably as they appear in the source material.