By the same; Histoire des Sultans du Kharezm, in Persian, by Defremery (Paris, 1842); History of the Atabeks of Syria and Persia, in Persian, by W.
In 1141 the assistance of this Khitaian prince was invoked by the shah of Kharezm against Sanjar, the Seljuk sovereign of Persia, who had expelled the shah from his kingdom and killed his son.
Though the Gur Khan himself is not described as having extended his conquests into Persia, the shah of Kharezm followed up the victory by invading Khorasan and plundering the cities and treasuries of Sanjar.
In Carpini's (1248) single mention of Prester John as the king of the Christians of India the Greater, who defeats the Tatars by an elaborate stratagem, Oppert recognizes Jalaluddin of Kharezm and his brief success over the Mongols in Afghanistan.
It was known to the ancient Arab and Persian geographers as the Sea of Khwarizm or Kharezm, from the neighbouring district of the Chorasmians, and derives its present name from the Kirghiz designation of Aral-denghiz, or Sea of Islands.