During the 7th to gth centuries the Tibetan Empire began to expandeastward with the military forces.The writer of the essay thinks that the efforts should be made to inv. estimate into the cultural factors in the eastward expansion of the Tibetancivilization. He holds that the main one is the cultural assimilating factorThe essay has offered for the readers the systexnatic elaboratioll andcomparison in the three aspects of nationality, language and econmicculture.
This paper studies the life story of a Uighur Tibetan XuanWeiShi, by name YeXianNai, of the Yuan dynasty according to a Tibetan article by BaSiBa in The Collected Works of the Five Sages of the Sakya Sect. It corrected the mistakes in TuJis A History of Mongol about YeXianNai as a Tibetan XuanWeiShi, and some related historical materials lacking in the Chinese historical records and unknown to many people.