The Shans are a distinct race from the Burmans. The existing Burmese people may be traced, it is said, to tribes dwelling in the Eastern Himalaya and the adjoining region of Thibet. The Tai or Siamese branch of the Indo-Chinese people, called Shan by the Burmese, are supposed to have migrated from their original seat in Central Asia towards the south, and to have settled along the rivers Mekong, Menam, Irrawaddy, and Brahmaputra. They are found as a distinct race from the borders of Manipur to the heart of Yunnan, and from the Valley of Assam to Bangkok and Cambodia. Major H. R. Davies found them occupying most of the low-lying valleys in Southern Yunnan, and on the Tongking border, and in small communities even in Northern Yunnan and on the Upper Yangtze. Although so widely spread, in some cases even scattered, and, except in Siam, subjected to alien races, they have preserved to a great extent a common language and national character.[34] In religion they are Buddhist of the Burmese type, but less strict in the observance of religious duties and ceremonies and less regardful of animal life. They are in many ways a civilized people, unwarlike, and given to agriculture and commerce. They are not unfriendly to foreigners. "I must have travelled," writes Major Davies, "some fifteen hundred miles through Shan countries, and I never remember any difference of opinion, or unpleasantness of any kind."[35] "It may be accepted as historical," says Phayre, "that the Tai race became supreme in the country of the Upper Irrawaddy early in the Christian Era and continued to be so under a consolidated monarchy for several centuries. About the ninth century A.D. it began to break up into separate States which eventually were conquered by the Burmans."[36] In the Irrawaddy Valley the Shans lost their autonomy, and were amalgamated with the Burman population; but those on the high plateau to the east continued to be governed by their own chiefs, according to their own customs, subject to the suzerainty of Burma. Some small States west of the Irrawaddy, survived the dissolution of the Shan kingdom, and they also enjoyed a similar but less marked independence.