Gregory IX (about 1155-1241) was elected pope in 1227. His most important accomplishment was publishing the first complete and authoritative collection of papal decrees in 1234. This collection remained the fundamental law of the Roman Catholic Church until a revised code was issued in 1917.
Gregory was born in Anagni, Italy. His given name was Ugolino. His uncle, Pope Innocent III, promoted him to the rank of cardinal in 1198. Gregory was the cardinal protector of the Franciscans, and he furthered the growth of the order before and after he became pope.
Gregory came into frequent conflict with Holy Roman Emperor Frederick II. Frederick had promised repeatedly to lead a crusade to the Holy Land. After he broke his promise again in 1227, Gregory excommunicated him. The next year, in spite of being excommunicated, Frederick led a successful crusade. Gregory concluded a peace treaty with Frederick in 1230. The pope renewed his excommunication in 1239 as part of the battle between the papacy and the empire for control of Italy. Gregory died on Aug. 22, 1241.
