 Hulagu Khan , a grandson of Genghis Khan , was an avowed shamanist , but was nevertheless very tolerant of Christianity . His mother <unk> Beki , his favorite wife Doquz Khatun , and several of his closest collaborators were Nestorian Christians . One of his most important generals , Kitbuqa , was a Nestorian Christian of the Naiman tribe . Military collaboration between the Mongols and their Christian vassals became substantial in 1258 – 1260 . Hulagu 's army , with the forces of his Christian subjects Bohemond VI of Antioch , Hethum I of Armenia , and the Christian Georgians , effectively destroyed two of the most powerful Muslim dynasties of the era : the Abbasids in Baghdad and the Ayyubids in Syria . 
