CLEMENT IV. (Gui Foulques), pope from 1265 to 1268, son of a lawyer, was born at St. Gilles-sur-Rhone. He became a valued legal adviser of Louis IX. of France, and after the death of his wife took orders. In 1257 he was made bishop of Le Puy, in 1259 archbishop of Narbonne, and in 1261 cardinal bishop of Sabina. He was appointed legate in England in 1263, and before his return was elected pope at Perugia on Feb. 5, 1265. He in vested the avaricious Charles of Anjou with the kingdom of Sicily, but subsequently came into conflict with him of ter the death of Manfred in Feb. 1266. When Conradin, the last of the Hohenstaufen, appeared in Italy the pope excommunicated him and his supporters. Clement died at Viterbo on Nov. 29, 1268, leaving a name unsullied by nepotism. As the protector of Roger Bacon he has a special title to the gratitude of posterity.
See A. Potthast, Regesta Pontificum Romanorum, vol. ii. (1875) , 1,542 ff.; E. Jordan, Les Registres de Clement IV. (1893 ff.) ; Herzog Hauck, Realencyklopadie; J. Heidemann, "Papst Clemens IV.," in Kirchengeschichtliche Studien, 6. Band (Munster, 19o3), and C. Nicholas, Clement IV. (Nimes, 1910) .