Ethnic groups The vast majority of Cambodia's population is of ethnic Khmer origin (over 95%) who are speakers of the Khmer language, the country's sole official language. Cambodia's population is largely homogeneous. Its minority groups include Chams (1.2%), Vietnamese (0.1%) and Chinese (0.1%). The largest ethnic group in Cambodia are the Khmers, who comprise around 90% of the total population in Cambodia, and are indigenous to the lowland Mekong subregion in which they inhabit. The Khmers historically have lived near the lower Mekong River in a contiguous diagonal arc, from where modern-day Thailand, Laos, and Cambodia meet in the northwest, all the way to the mouth of the Mekong River in southeastern Vietnam. The Vietnamese are the second-largest ethnic minority in Cambodia, with an estimated 16,000 living in provinces concentrated in the southeast of the country adjacent to the Mekong Delta. Although the Vietnamese language has been determined to be a Mon–Khmer language, there are very few cultural connections between the two peoples because the early Khmers were influenced by the Indian cultural sphere while the Vietnamese are part of the Chinese cultural sphere. Ethnic tensions between the Khmer and the Vietnamese can be traced to the Post-Angkor Period (from the 16th to 19th centuries), during which time a nascent Vietnam and Thailand each attempted to vassalise a weakened post-Angkor Cambodia, and effectively dominate all of Indochina. Chinese Cambodians are approximately 0.1% of the population. Most Chinese are descended from 19th–20th-century settlers who came in search of trade and commerce opportunities during the time of the French protectorate. Most are urban dwellers, engaged primarily in commerce. The indigenous ethnic groups of the mountains are known collectively as Montagnards or Khmer Loeu, a term meaning "Highland Khmer". They are descended from neolithic migrations of Mon–Khmer speakers via southern China and Austronesian speakers from insular Southeast Asia. Being isolated in the highlands, the various Khmer Loeu groups were not Indianized like their Khmer cousins and consequently are culturally distant from modern Khmers and often from each other, observing many pre-Indian-contact customs and beliefs. The Cham are descended from the Austronesian people of Champa, a former kingdom on the coast of central and southern present-day Vietnam and former rival to the Khmer Empire. The Cham in Cambodia number under a million and often maintain separate villages in the southeast of the country. Almost all Cham in Cambodia are Muslims. Largest cities Women Khmer