is imposing in their eyes call Tengri, such as a great mountain or tree, and they bow down to such things." Sociologist Rakhat Achylova studied how aspects of Tengrism were adopted into a Kyrgyz form of Islam. Tengrism and Christianity Hulegu Khan sent a letter in Latin to King Louis IX of France on April 10, 1262, from his capital Maragheh in Iran. Kept in the Vienna National Library as MS 339 it is both an invitation for joint operations against the Mamluks as well as an imperious command to submit. The letter provides key insights into the Mongols' understanding of Tengrism's relationship to Christianity as well as furnishing one of the first Latin transcriptions of Tengri. Only a few sentences from the lengthy letter are shown below (those with relevancy to Tengrism): The letter largely propounds the usual Mongol ideology and understanding of Tengrism with mentions of the supreme shaman Kokochu Teb Tengri. All meanings of Tengri including the sky, the most high God and "a god" are implied in the letter. Jesus Christ is called Misicatengrin or Messiah-Tengri in the letter. The Misica is from Syriac mshiha (Messiah, Christ) as opposed to Arabic masih. Another Syriac word in the letter is Barachmar (greetings). This points to the well-known Nestorian heritage within the Mongol Empire which used Syriac as its liturgical language. The Mongolian letter of Arghun Khan to Pope Nicholas IV (1290) also uses the word Misica for Christ. William of Rubruck reported that Arig Boke, brother of Hulegu Khan, used the word Messiah near Karakorum in 1254 (Then they began to blaspheme against Christ, but Arabuccha stopped them saying: "You must not speak so, for we know that the Messiah is God"). There are elements of syncretism between Tengrism and Nestorian Christianity with overlapping notions of monotheism and a traditional view of Christ as Misicatengrin probably dating back to the Keraite conversion in 1007. In Hulegu's letter Tengrism takes the overarching, non-dogmatic role and contains Nestorianism as a compatible subset, in line with the religious pluralism practiced by the Mongols. Hulegu himself was not strictly a Christian, although his wife, his general Kitbuqa and mother were Nestorians. He was a Tengriist whose Nestorian interests were of the Mongol, syncretic type. His successor Abaqa Khan would take part in the Ninth Crusade with the future King Edward of England in 1271 and also storm the Krak des Chevaliers