Thailand is a country of some 70 ethnic groups, including at least 24 groups of ethnolinguistically Tai peoples, mainly the Central, Southern, Northeastern, and Northern Thais; 22 groups of Austroasiatic peoples, with substantial populations of Northern Khmer and Kuy; 11 groups speaking Sino-Tibetan languages ('hill tribes'), with the largest in population being the Karen; 3 groups of Austronesian peoples, i.e., the Malay, the majority ethnic group in the southernmost three provinces, together with the Moken and Urak Lawoi ('sea gypsies'); and both groups of Hmong-Mien. Other ethnic groups include longstanding immigrant communities such as the Chinese, Indians and . Historical development Background 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, 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. The arrival of the Tai 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 The most powerful to emerge was Ayutthaya, which superseded Sukhothai in the 16th century.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. The nation-building era Under the Bangkok-based Chakri dynasty, Siam formally