# 1911 Encyclopædia Britannica/Gregory (Popes)/Gregory IX

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​Gregory IX. (Ugolino Conti de Segni), pope from the 19th of March 1227, to the 22nd of August 1241, was a nobleman of Anagni and probably a nephew of Innocent III. He studied ​at Paris and Bologna, and, having been successively archpriest of St Peter’s, papal chaplain, cardinal-deacon of Sant’ Eustachio, cardinal-bishop of Ostia, the first protector of the Franciscan order, and papal legate in Germany under Innocent III., and Honorius III., he succeeded the latter in the papacy. He had long been on friendly terms with the emperor Frederick II., but now excommunicated him (29th of September 1227) for continued neglect of his vows and refusal to undertake the crusade. When Frederick finally set out the following June without making submission to the pope, Gregory raised an insurrection against him in Germany, and forced him in 1230 to beg for absolution. The Romans, however, soon began a very bitter war against the temporal power and exiled the pope (1st of June 1231). Hardly had this contest been brought to an end favourable to the papacy (May 1235) when Gregory came into fresh conflict with Frederick II. He again excommunicated the emperor and released his subjects from their allegiance (24th of March 1239). Frederick, on his side, invaded the Papal States and prevented the assembling of a general council convoked for Easter 1241. The work of Gregory, however, was by no means limited to his relations with emperor and Romans. He systematized the Inquisition and entrusted it to the Dominicans; his rules against heretics remained in force until the time of Sixtus V. He supported Henry III. against the English barons, and protested against the Pragmatic Sanction of Louis IX. of France. He sent monks to Constantinople to negotiate with the Greeks for church unity, but without result. He canonized Saints Elizabeth of Thuringia, Dominic, Anthony of Padua and Francis of Assisi. He permitted free study of the Aristotelian writings, and issued (1234), through his chaplain, Raymond of Pennaforte, an important new compilation of decretals which he prescribed in the bull Rex pacificus should be the standard text-book in canon law at the universities of Bologna and Paris. Gregory was famed for his learning and eloquence, his blameless life, and his great strength of character. He died on the 22nd of August 1241, while Frederick II. was advancing against him, and was succeeded by Celestine IV.
For the life of Gregory IX., consult his Letters in Monumenta Germaniae historica, Epistolae saeculi XIII. e regestis pontif. Roman. selectae (Berlin, 1883); “Les Registres de Grégoire IX,” ed. L. Auvray in Bibliothèque des écoles françaises d’Athènes et de Rome (Paris, 1890–1905); A. Potthast, Regesta pontif. Roman. (Berlin, 1875) and “Registri dei Cardinali Ugolino d’ Ostia et Ottaviano degli Ubaldini,” ed. G. Levi in Fonti per la storia d’ Italia (1890). See J. Felten, Papst Gregor IX. (Freiburg i. B., 1886); J. Marx, Die Vita Gregorii IX. quellenkritisch untersucht (1889); P. Balan, Storia di Gregorio IX e dei suoi tempi (3 vols., Modena, 1872–1873); F. Gregorovius, Rome in the Middle Ages, vol. 5, trans. by Mrs G. W. Hamilton (London, 1900–1902); H. H. Milman, Latin Christianity, vol. 5 (London, 1899); R. Honig, Rapporti tra Federico II e Gregorio IX rispetto alla spedizione in Palestina (1896); P. T. Masetti, I Pontefici Onorio III, Gregorio IX ed Innocenzo IV a fronte dell’ Imperatore Federico II nel secolo XIII (1884); T. Frantz, Der grosse Kampf zwischen Kaisertum u. Papsttum zur Zeit des Hohenstaufen Friedrich II. (Berlin, 1903); W. Norden, Das Papsttum u. Byzanz (Berlin, 1903). An exhaustive bibliography and an excellent article on Gregory by Carl Mirbt are to be found in Hauck’s Realencyklopädie, 3rd edition.