GREGORY IX., pope from 1227 to 1241, the successor of Honorius III., fully inherited the traditions of Gregory VII. and of his uncle Innocent III., and zealously gave himself up to the perpetuation of their policy. One of the first acts of his pontificate was to suspend the emperor Frederick H., then lying sick at Otranto, for dilatoriness in carrying out his promised crusade ; the suspension was followed by excommunication and threats of deposition after Frederick had written to the sovereigns of Europe complaining of his treatment, A consequent invasion of the patrimony of St Peter at the instance of Frederick in 1228 having proved unsuccessful, the emperor was constrained to give in his submission and beg for absolution. Although peace was thus secured (August 1230) for a season, the Roman people were far from satisfied ; driven by a revolt from his own capital in July 1232, the pope was compelled to take refuge at Anagni and invoke the aid of Frederick. A new outbreak of hostility led to a fresh excommunication of the emperor in 1239, and to a prolonged war which was only terminated by the death of Gregory (August 22, 1241). This pope, who was a remarkably skilful and learned lawyer, caused to be prepared in 1234 the well known Nova Compilatio Decretaliurn, printed at Mainz in 1473. He it was who canonized Saints Elizabeth, Dominic, and Antony of Padua, and also Francis of Assisi, of whom he had been a personal friend. His encroachments upon the rights of the English Church during the ignominious reign of Henry III. are well known; but similar attempts against the liberties of the national church of France only served to call forth the celebrated Pragmatic Sanction of St Louis. Gregory IX. was succeeded by Celestine IV.