Gregory IX summary

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Gregory IX, orig. Ugo di Segni, (born before 1170—died Aug. 22, 1241, Rome), Pope (1227–41) who founded the papal Inquisition. In 1227 he excommunicated Frederick II when the emperor delayed in keeping his pledge to lead a Crusade. Gregory ordered an attack on the kingdom of Sicily in the emperor’s absence, but his forces were defeated. In 1234 he published the Decretals, a code of canon law that remained fundamental to Catholicism until World War I. Attacking heresy in southern France and northern Italy, he strengthened the Inquisition. Frederick’s invasion of Sardinia, a papal fief, led Gregory to renew his excommunication (1239); he sought support in northern Italy but died before the struggle was resolved.

Roman Catholicism Summary

Roman Catholicism, Christian church that has been the decisive spiritual force in the history of Western civilization. Along with Eastern Orthodoxy and Protestantism, it is one of the three major branches of Christianity. It is led by the pope, as the bishop of Rome, and the Holy See forms the

Christianity Summary

Christianity, major religion stemming from the life, teachings, and death of Jesus of Nazareth (the Christ, or the Anointed One of God) in the 1st century ce. It has become the largest of the world’s religions and, geographically, the most widely diffused of all faiths. It has a constituency of

canon law Summary

Canon law, body of laws made within certain Christian churches (Roman Catholic, Eastern Orthodox, independent churches of Eastern Christianity, and the Anglican Communion) by lawful ecclesiastical authority for the government both of the whole church and parts thereof and of the behaviour and

church and state Summary

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