Pope Urban II (;  – 29 July 1099), otherwise known as Odo of Châtillon or Otho de Lagery, was the head of the Catholic Church and ruler of the Papal States from 12 March 1088 to his death. He is best known for convening the Council of Clermont which ignited the series of Christian conquests known as the Crusades.Richard Urban Butler (1912). "Pope Bl. Urban II". In Catholic Encyclopedia. 15. New York: Robert Appleton Company.Theodore Freylinghuysen Collier (1911). "Urban (popes)". In Chisholm, Hugh (ed.). Encyclopædia Britannica. 27. (11th ed.), Cambridge University Press. pp. 789–792.
