sentences:  One of his most important generals, Kitbuqa, was a Nestorian Christian of the Naiman tribe.In 1238, the European kings Louis IX of France and Edward I of England rejected the offer of the Nizari Imam Muhammad III of Alamut and the Abbasid caliph Al-Mustansir for a Muslim–Christian alliance against the Mongols.They later joined the Mongols against all Muslims.