1231 AD
Pope Gregory IX established the Papal Inquisition in 1231 through the bull 'Ille humani generis,' creating a formal system of ecclesiastical courts to investigate and try cases of heresy. The Inquisition was staffed primarily by Dominican friars, who were chosen for their learning and piety. The procedures, while harsh by modern standards, were actually more legalistic and fair than secular courts of the timeβdefendants had the right to counsel, to present evidence, and to appeal.
The medieval Inquisition focused primarily on combating heresies such as Catharism, Waldensianism, and Judaizing (Jews who had converted to Christianity but secretly practiced Judaism). While torture was authorized in 1252 by Pope Innocent IV, it was regulated and limited. The majority of cases resulted in penances such as wearing crosses, attending Mass, or doing penitential pilgrimages.
Modern historians estimate that over the entire history of the medieval Inquisition (roughly 1231-1500), approximately 3,000-5,000 people were executedβfar fewer than the hundreds of thousands claimed by Protestant propaganda. Key Sources: Henry Kamen, The Spanish Inquisition: A Historical Revision; Edward Peters, Inquisition; Jacques Le Goff, The Medieval Persuasion