Thailand there lived in Central Thailand or the Menam Basin, in or about the 5th to the 7th century A.D., a people probably akin to the Mons of Lower Burma. They are known archaeologically by the name of their kingdom, in the 12th century A.D. became part of the Khmer Empire and later on in the 13th century A.D. passed from the rule of the now decaying Khmer Empire to that of the Thai of Sukhodaya. Further south, in which is now Central Thailand in the Menam valley or Chao Phya Basin, there were evidently some settlements of the Thai people. At first they were minority groups named Thai-Noi. Thailand, we deal with the common history of all Thai-speaking people to an identical extent as with the history of Laos and Shans in particular. Evidence of a kingdom known to the Chinese as Nan-chao meaning lord. Nan-Chao kingdom was a comparatively powerful state with a high level of culture. It lasted for some seven centuries until it fell in 1253 A.D. "A history of South -East Asia" says that the Thai never ceased to be on the move. (from the earlier days of Nan-Chao)