Callixtus II, né Guido of Vienne (d. December 13, 1124), the son of William I, Count of Burgundy, was elected Pope on February 2, 1119, after the death of Gelasius II.
In 1088, he became the Archbishop of Vienne. He held strong views about the Investiture Crisis, but was willing to negotiate with Henry V, the Holy Roman Emperor.
In 1122 he concluded the Treaty of Metz with Henry V, by which the mutual rights of the church and the Empire were finally settled.
On September 23 of that year, the Concordat of Worms was agreed upon. The future emperor Honorius II was one of the papal negotiators.
Callixtus II died in December 1124.
References
Some material adapted from the 9th edition (1876) of the Encyclopædia Britannica