Who called the council, and why?

The council was called by Pope Callixtus to settle church and state relations after the Concordat of Worms.


The Concordat of Worms was an agreement between Pope Callixtus and Holy Roman Emperor Henry V that brought the first phase of the power struggle between the Papacy and the Holy Roman Emperors to an end and has been interpreted as containing the germ of nation-based sovereignty.