Person
Pope Calixtus II
head of the Catholic Church
Pope Blessed Calixtus II (or Calistus II) (died 13 December 1124), born Guy de Burgundy, the fourth son of William I, Count of Burgundy, is elected Pope on 1 February 1119 after the death of Pope Gelasius II.
His pontificate is shaped by the Investiture Controversy, which he is able to settle through the Concordat of Worms (in 1122).