GREGORY VIII. (_Alberto de Mora_), pope from the 21st of October to the 17th of December 1187, a native of Benevento and Praemonstratensian monk, successively abbot of St Martin at Laon, cardinal-deacon of San' Adriano al foro, cardinal-priest of San Lorenzo in Lucina, and chancellor of the Roman Church, was elected to succeed Urban III. Of amiable disposition, he hastened to make peace with Henry VI. and promised not to oppose the latter's claim to Sicily. He addressed general letters both to the bishops, reminding them of their duties to the Roman Church, especially of their required visits _ad limina_, and to the whole Christian people, urging a new crusade to recover Jerusalem. He died at Pisa while engaged in making peace between the Pisans and Genoese in order to secure the help of both cities in the crusade. His successor was Clement III. His letters are in J. P. Migne, _Patrol. Lat._ vol. 202. Consult also J. M. Watterich, _Pontif. Roman. vitae_, vol. 2 (Leipzig, 1862), and Jaffe-Wattenbach, _Regesta pontif. Roman._ (1885-1888). See J. Langen, _Geschichte der romischen Kirche von Gregor VII. bis Innocenz III._ (Bonn, 1893); P. Nadig, _Gregors VIII. 57 tagiges Pontifikat_ (Basel, 1890); P. Scheffer-Boichorst, _Friedrichs I. letzter Streit mit der Kurie_ (Berlin, 1866); F. Gregorovius, _Rome in the Middle Ages_, vol. 4, trans. by Mrs G. W. Hamilton (London, 1896). 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