The last of the great Seljuk sultans, who ruled the empire's eastern heartland of Khurasan for decades before its power fractured around him.
Life
Ahmad Sanjar (effective ruler of the east from 1097, sultan 1118–1157) governed Khurasan and the Seljuk east through a long reign of both splendor and mounting crisis. He faced the rise of the Kara-Khitai, who defeated him at the Qatwan steppe (1141), and finally a revolt of Oghuz Turkmen who captured and held him prisoner. His death in 1157 effectively ended the Great Seljuk Empire, which dissolved into successor states.