Thai people, who originally lived in southwestern China, migrated into mainland Southeast Asia over a period of many centuries. The oldest known mention of their existence in the region by the exonym Siamese is in a 12th-century A.D. inscription at the Khmer temple complex of Angkor Wat in Cambodia, which refers to syam, or "dark brown", people.[1] It was believed that Siam derived from the Sanskrit word syam, or "brown race", with a contemptuous signification. Sien in Chinese writings is the name for the northern kingdom that centered on Sukhothai and Sawankalok; but to the Siamese themselves, the name of the country has always been Mueang Thai.[2]