Gregory IX

Gregory IX (circa 1147?-1241), pope (1227-41), who founded the Inquisition.

He was born Ugolino de Segni in Anagni, Italy. After studying in Paris and Bologna, he was made a cardinal by his uncle, Pope Innocent III, in 1198. His own pontificate was marked by conflict with Holy Roman Emperor Frederick II, who sought to strengthen the imperial position in Italy, thus posing a constant threat to the papacy. When Gregory called on Frederick to fulfill an old promise to embark on a crusade, Frederick delayed, claiming illness. Gregory promptly excommunicated him. The conflict grew, was never fully resolved, and continued until Gregory's death on August 22, 1241.

Gregory was a personal friend of St. Dominic and St. Francis of Assisi. Profoundly troubled by the Albigensian heresy, Gregory in 1231 issued the constitution Excommunicamus, which placed the prosecution of heretics under papal direction and thus established the Inquisition . Gregory also ordered the collection of the decretals, papal decisions on matters of discipline; this was a step toward codifying canon law.