orig. Guido of Burgundy
died Dec. 13/14, 1124, Rome
Pope (1119–24).
As archbishop of Vienne in Lower Burgundy, he became known as an advocate of reform and an opponent of Holy Roman emperor Henry V. Elected pope in 1119, he condemned lay investiture and excommunicated Henry. They were later reconciled, and the Concordat of Worms (1122) ended the Investiture Controversy . Calixtus called the first Lateran Council (1123), which secured peace between church and empire for the next 35 years. His bull Etsi Judaeis (1120) protected Roman Jews.