Ethnic groups in Thailand

Thailand was mainly inhabited by indigenous Austro-Asiatic (Mon-Khmer, Khmu, and Lawa) peoples in the central plains and Northeast, and in the South by Malayo-Sumbawan (Malay) peoples, until the Tai arrived. Following the arrival of the Tai, Sino-Tibetan peoples (Hmong and Mien) arrived in the West and North from China (Guizhou), either via Laos or Vietnam and then Lao, or in the case of the Loloish Tibeto-Burman peoples (Akha, Lahu), over several centuries up until approximately the twentieth century. The Karen, another Tibeto-Burman people, arrived at and began populating the border between Burma and Siam in the 13th century. Thailand also became home to large numbers of Thai Chinese during the main period of Chinese emigration.[1]

From approximately the 7th until the 13th centuries, the Tai, who may have originated in what is now Guangxi in China and bordering areas of Northwest Vietnam, gradually populated the Mekong, Chao Praya, and Salween river valleys, fuelled by a sophisticated rice production system. Strong Tai societies emerged on the Shan plateau in upper Myanmar, along the Mekong in the north in Xishuangbanna, in the Yuan empire of Lan Na, and in the Middle Mekong in the Lao empire of Lan Xang. These societies subsequently developed into polities, for example Chiang Mai, the capital of Lan Na, and Sukhothai. The most powerful to emerge was Ayutthaya, which superseded Sukhothai in the 16th century. From the 16th to the 18th centuries the Burmese expanded east, occupying Lan Na and parts of the Xishuangbanna and eventually destroying Ayutthaya. Nonetheless, Thonburi, the Tai successor state to Ayutthaya, established suzerainty over the Lanna, Luang Prabang, and Malay states and thereby defeated the Burmese, ensuring the primacy of the Tai ethnic groups in the region.[1]

Under the Bangkok-based Chakri dynasty, Siam formally incorporated and integrated large numbers of ethnically Laotian people, themselves formed of various subgroups. Siam brought the remaining Lan Xang city-states of Vientiane (destroyed in 1827) and Champasak under direct control in the 19th century. What remained of Lan Na became a vassal until 1896, when it was formally annexed, incorporating large numbers of Kham muang speakers, together with the various ethnic groups sometimes called 'hill tribes', such as the Karen.[1]

In the Malay Peninsula, Siam extended formal rule over large numbers of Malay people. In 1816, Siam divided the Muslim tributary Sultanate of Patani into seven provinces as part of a policy of 'divide and rule'. Via administrative modernisation, in 1901 Siam incorporated all seven provinces into ‘Monthon Patani’, under the new Ministry of Interior. When Kedah was ceded to the English under the Anglo–Siamese Treaty of 1909, in exchange for what became Satun Province, Thailand thereby cemented its official rule over hundreds of thousands of Malay people.[2][1]

Siamese suzerainty over present-day Laos, together with some Cambodian provinces, was permanently ceded to the French during the formation of French Indochina. In the early Chakri dynasty period, Siamese armies had invaded areas of Laos and returned with large numbers of prisoners of war, especially Phuan and Tai Dam peoples, who were subsequently resettled in the central plains. During the nation-building era, Siam's ethnic map became more varied, as the majority of the peoples of the Khorat plateau, once part of Lan Xang empire, were formally integrated into Siam, incorporating more Lao, Khorat, and Phu Thai, but also smaller ethnic groups such as the Yoy and So, together with the Khmu, Kuy, and Nyahkur along the Khmer border.[1]

As part of Chinese emigration, Thailand received Chinese immigrants over several hundred years, and especially during the nineteenth and early twentieth centuries, until the 1930s, meaning many Thai urban centres now have ethnically Chinese populations (mainly Teochew speakers).[3][1]

The 1904 Siamese census deliberately omitted the Lao ethnic identity so as to discourage further French colonial predations, resulting in the Thai officially becoming 85% of the population by ethnicity, rising to 89% in 1912.[4] In the 1900s, membership of the Thai 'race' came to form the basis of citizenship of the modern Thai nation-state.[5] In the 1930s, Thai nationalist Luang Wichitwathakan developed ethnocentric policy which came to equate the Tai linguistic family with a greater pan-Thai race-based ‘nation.’ The first of the 12 Cultural Mandates, of June 24, 1939, renamed Siam ‘Thailand’, or as it was during the Second World War, the ‘Great Thai Empire’, an assertion of Thai imperial identity over subject peoples.[6] Then, in 1943, the influential National Culture Commission, which has survived in various incarnations until the present day (as the Thai Ministry of Culture) was established in order to define and disseminate official Thai national culture.[1]

Thailand received an influx of tens of thousands of Vietnamese after the end of the French Indochina war. During the Cold War, further nation-building resulted in a polity where 'Thai' and 'Tai' continued to be deliberately conflated and, in the official discourse, nearly everyone was ethnically Thai and so spoke Thai or Thai ‘dialects’, as the regional languages and most smaller Tai languages were described.[7] From the 1960s, census data described up to 99% of the population as ethnically Thai.[1] Nonetheless, academic research of the Cold War period suggests that of these, only 33% spoke Central Thai, with over 50% speaking Lao dialects (Isan), an indication of the number of ethnic Lao or users of Lao as a second language or lingua franca for the Northeast.[8] Thai censuses still do not disaggregate by either the largest or smallest ethnic groups and so reflect Thai national identity rather than the scientific consensus.[1] Thailand saw an influx of a large number of Northern Khmer during the rule of the Khmer Rouge, some of whom permanently settled with indigenous Khmer.[1]