the clan of Chu Bo,Mongolian Lord Bin,was the offspring of Chagatai Khanate.They broke away from Chagatai Khanate and submitted to Kublai Khan from 1277 to 1282.They were entrusted with the important task to garrisoning the Suzhou,Guazhou,and Hami regions at the west end of the Hexi Corridor,the front line of defending against rebellions of the other lords such as Ogadai Khan and Chagatai Khan.The Yuan dynasty Chinese documents from Khara-Khoto,including F116:W561,TK204,and TK248,suggest that Ejina Prefecture,which enjoyed a special geographical position and served as the place for military buildup and material supply,became an important fortress on the northwestern defense line,and kept a close relation with the clan of Lord Bin,who were active in that region.They worked together to enhance the stability of the northwestern border.
