It’s 1481. In the city of Seville, devout Catholics are turning themselves  in to the authorities. They’re confessing to heresy— failure to follow the beliefs of the Catholic Church. But why? The Spanish Inquisition has arrived in Seville. The Inquisition began in 1478,  when Pope Sixtus IV issued a decree authorizing the Catholic monarchs,  Ferdinand and Isabella, to root out heresy in the Spanish kingdoms— a confederacy of semi-independent kingdoms in the area that would become the modern country of Spain. Though the order came from the church, the monarchs had requested it. When the Inquisition began,  the Spanish kingdoms were diverse both ethnically and religiously, with Jews, Muslims, and Christians living in the same regions. The Inquisition quickly turned its attention to ridding the region of people who were not part of the Catholic Church. It would last more than 350 years. On the ground, groups called tribunals ran the Inquisition in each region. Roles on a tribunal could include an arresting constable,  a prosecuting attorney, inquisitors to question the accused, and a scribe. A “Grand Inquisitor,” a member of the  clergy selected by the king and queen, almost always led a tribunal. The Inquisition marked its arrival in each new place with an “Edict of Grace.” Typically lasting 40 days, the Edict of Grace promised mercy to those who confess to heresy. After that, the inquisitors persecuted suspected heretics on the basis of anonymous accusations. So the confessors in Seville probably didn’t see themselves as actual heretics— instead, they were hedging their bets by reporting themselves when the consequences were low, rather than risking  imprisonment or torture if someone else accused them later on. They were right to worry: once the authorities arrested someone,  accusations were often vague, so the accused didn’t know the reasons  for their arrest or the identity of their accuser. Victims were imprisoned  for months or even years. Once arrested,  their property was confiscated, often leaving their families on the street. Under these conditions, victims confessed to the most mundane forms of heresy— like hanging linen to dry on a Saturday. The Inquisition targeted different subsets of the population over time. In 1492, at the brutal Grand Inquisitor Tomás de Torquemada’s urging, the monarchs issued a decree giving  Spanish Jews four months to either convert to Christianity or leave the kingdom. Thousands were expelled  and those who stayed risked persecution. Converts to Christianity, known as conversos, weren’t even safe, because authorities suspected  them of practicing Judaism in secret. The hatred directed at conversos was both religious and economic, as conversos made up a large portion of the upper middle class. The Inquisition eventually shifted its focus to the moriscos, converts to Christianity from Islam. In 1609, an edict passed forcing all moriscos to leave. An estimated 300,000 left. Those who remained became  the Inquisition’s next targets. The inquisitors announced the punishments of those found guilty of heresy in public gatherings called autos de fé, or acts of faith. Hundreds of people gathered to watch  the procession of sinners, mass, sermon, and finally the announcement of punishments. Most of the accused received punishments like imprisonment, exile, or having to wear a sanbenito,  a garment that marked them as a sinner. The worst punishment  was “relaxado en persona”— a euphemism for burning at the stake. This punishment was relatively uncommon— reserved for unrepentant and relapsed heretics. Over 350 years after Queen Isabella started the Inquisition, her namesake, Queen Isabella II,  formally ended it on July 15th, 1834. The Spanish kingdoms’ dependence  on the Catholic Church had isolated them while the rest of Europe experienced the Enlightenment and embraced the separation  of church and state. Historians still debate the number  of people killed during the Inquisition. Some suggest over 30,000  but most estimate between 1,000 and 2,000. The consequences of the Inquisition, however, reach far beyond fatalities. In some places, an estimated 1/3 of prisoners were tortured. Hundreds of thousands of members  of religious minorities were forced to leave their homes, and those who remained faced  discrimination and economic hardship. Smaller inquisitions in Spanish  colonial territories in the Americas, especially Mexico, carried their own tolls. Friends turned in friends,  neighbors accused neighbors, and even family members reported each other of heresy. Under the Inquisition, people were condemned to live  in fear and paranoia for centuries.