The History of the Yuan mentions an embassy from the kingdom of Sukhothai in 1282.In 1287, three Thai chiefs, Mangrai, Ngam Muang, and Ram Khamhaeng formed a "strong pact of friendship".The Thai National Anthem (Thai: ), written by Luang Saranupraphan during the extremely patriotic 1930s, refers to the Thai nation as: prathet Thai (Thai: ประเทศไทย).The first line of the national anthem is: prathet thai ruam lueat nuea chat chuea thai (Thai: There is evidence of human habitation in Thailand that has been dated at 40,000 years before the present, with stone artifacts dated to this period at Tham Lod Rockshelter in Mae Hong Son.According to George Cœdès, the word Thai (ไทย) means "free man" in the Thai language, "differentiating the Thai from the natives encompassed in Thai society as serfs.") means "kingdom of Thailand" or "kingdom of Thai".Etymologically, its components are: ratcha (Sanskrit राजन्, rājan, "king, royal, realm") ; -ana- (Pali āṇā "authority, command, power", itself from the Sanskrit आज्ञा, ājñā, of the same meaning) -chak (from Sanskrit चक्र cakra- "wheel", a symbol of power and rule).
It is the 20th-most-populous country in the world, with around 69 million people.
By outsiders prior to 1949, it was usually known by the exonym Siam (Thai: with the Sanskrit Śyāma (श्याम, meaning "dark" or "brown").
The names Shan and A-hom seem to be variants of the same word.
According to the Encyclopædia Britannica, "A quarter to a third of the population of some areas of Thailand and Burma were slaves in the 17th through the 19th centuries." This has been ascribed to the long succession of able rulers in the past four centuries who exploited the rivalry and tension between the French and British Empire.
In 1896, Britain and France guaranteed of the Chao Phraya valley as their buffer state (not the whole of Siam), while the remaining parts of Southeast Asia were colonized by the western powers.
The Chinese called this region Xian, which the Portuguese converted into Siam." (Baker and Phongpaichit, A History of Thailand, 8) A further possibility is that Mon-speaking peoples migrating south called themselves 'syem' as do the autochthonous Mon-Khmer-speaking inhabitants of the Malay Peninsula. 1851–1868) reads SPPM (Somdet Phra Poramenthra Maha) Mongkut King of the Siamese, giving the name "Siam" official status until 24 June 1939 when it was changed to Thailand.