Pope Callixtus II or Callistus II ( – 13 December 1124), born Guy of Burgundy, was head of the Catholic Church and ruler of the Papal States from 1 February 1119 to his death in 1124. His pontificate was shaped by the Investiture Controversy, which he was able to settle through the Concordat of Worms in 1122. As son of Count William I of Burgundy, Guy was a member of and connected to the highest nobility in Europe. He became archbishop of Vienne and served as papal legate to France. He attended the Lateran Synod of 1112. He was elected pope at Cluny in 1119. The following year, prompted by attacks on Jews, he issued the bull Sicut Judaeis which forbade Christians, on pain of excommunication, from forcing Jews to convert, from harming them, from taking their property, from disturbing the celebration of their festivals, and from interfering with their cemeteries. In March 1123, Calixtus II convened the First Lateran Council which passed several disciplinary decrees, such as those against simony and concubinage among the clergy, and violators of the Truce of God. Early life Born the fourth son of Count William I of Burgundy, one of the wealthiest rulers in Europe, Guy was a member of the highest aristocracy in Europe. His family was part of a network of noble alliances. He was a cousin of Arduin of Ivrea, the king of Italy. One sister, Gisela, was married to Count Humbert II of Savoy and then to Renier I of Montferrat; another sister, Maud, was the wife of Duke Odo I of Burgundy. Another sister, Clementia, married Count Robert II of Flanders. His brother Raymond was married to Urraca, the queen of León, and fathered the future King Alfonso VII of León. His brother Hugh was archbishop of Besançon. Archbishop of Vienne Guy first appears in contemporary records when he became the archbishop of Vienne in 1088. He held strong pro-papal views about the Investiture controversy. As archbishop, he was appointed papal legate to France by Pope Paschal II during the time that Paschal was induced under pressure from Holy Roman Emperor Henry V to issue the Privilegium of 1111, by which he yielded much of the papal prerogatives that had been so forcefully claimed by Pope Gregory VII in the Gregorian Reforms. These concessions were received with violent opposition and nowhere more so than in France, where the