With a population estimate exceeding 62 million that includes 75 ethnic groups and various peoples such as hill tribes and inhabitants of the northern mountain areas, you bet Thailand is a demographically diverse country. Thai is the national language, but seven Austronesian languages are spoken (all belonging to the Malayic Malayo-Polynesian group of languages) and there are 19 Tibeto-Burman speaking groups as well as various migrant communities that speak Korean, Japanese, Tamil, and Urdu. The country is often portrayed as one of cultural homogeny, but there are those ethnic groups previously mentioned as well as the Thai-Lao and Lanna Tai who (combined) account for about 40 percent of the population. A lot of this diversity can be attributed to the early migration (as early as the fifth or sixth century) of peoples from northern Vietnam and southern Yunnan into areas along the Mekong River. The Tai in northern Thailand came into contact with the Mon who then converted them to Theravada Buddhism. The founder of the kingdom of Ayutthaya promoted this practice and compiled a legal code based on its sources. In the 20th century the Central Thai culture emerged as the dominant national culture and the term “Thai Identity” was coined in the late 1950′s. A National Culture Commission was formed in 1979 to coordinate efforts to defend the “Thai Identity” and have been linked to national security and communist insurgency involving members of various ethnic minorities which is sure to be expected from a country with a population of its size. There continues to be a level of discrimination against the hill tribes (which are widely viewed as being involved in narcotics trafficking); however, the Tribal Assembly of Thailand has lobbied the government for greater transparency in decisions affecting those tribes, especially in regard to the granting of citizenship and land issues.