The mighty Abbasid Caliphate had disintegrated into a collection of warring city states, while Shi'ite authorities had come to dominate the Muslim world.  A new power was rising in the East, however, which would bring about a Sunni revival and stretch to the gates of the Byzantine Empire.  The rising Seljuk Turkish state would come to dominate the Caliphate, institute a new era of Sunni conservatism and frighten Europe enough to spark the Crusades.