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. Present, Northern Area of Thailand in many small independent states ruled by kingdom first king Mengrai. Further south, in which is now Central Thailand in the Menam valley or Chao Phya Basin, under the dominant rule of the Khmer Empire in about the 12th century A.D. The Thai of Center Thailand are named Thai-Noi. In 1350 A.D. there arose a new Thai power in the south of Sukhodaya proper, Ramadhibodi I, known vulgarly as King U-Thong, the first King of Ayudhya. Northern Thailand where King Mengrai reigned as its first king in the 13th century A.D. but later on in the latter part of the 16th century A.D. It became a part of the Burmese Empire for some two centuries. Thailand, with Ayudhya as its capital and its succession of kings both weak and strong,endured for 417 years and came to an end in 1767 A.D. through a war with Burma. and enter a new phase of progressive revolution following the Western trend which is a matter of modern history.