Cambodia, also known for a time as Kampuchea, is located in mainland Southeast Asia between Vietnam, Laos, Thailand, and the Gulf of Thailand. The KHMER, who are thought to have migrated from southern China prior to 200 BC, constitute more than 85% of the population. The chief minority groups are the Chinese and the Vietnamese. It is unclear how various upland minorities, such as the Cham-Malays and Khmer Loeus live in Cambodia. From the 9th to the 15th century the KHMER EMPIRE extended its sway far beyond the country's present boundaries.
This period produced the glorious temple complex and royal palace at ANGKOR. Five significant periods can be discerned in the history of Cambodia. From the 1st century AD, the kingdoms of Funan organized life in support of royal courts that adopted the Indian Brahmanic cult of the god-king; Indic culture spread into the legal code and an alphabet. During the 6th and 7th centuries, kingdoms of Khmer origin known as Chenla kept the institutions of Funan while conquering neighboring kingdoms in present-day Laos, Vietnam, and Thailand.
Chenla was succeeded by the classical (Angkor) period of Khmer history, which lasted from the 9th to the mid-15th century. During this period Cambodian artistic, architectural, and military achievements reached their zenith. A gradual decline in the coercive authority of the Khmer Empire was followed by losses of territory to the Vietnamese and the Thais. The Khmer kingdom gradually declined; it accepted French protection in 1863 and was later incorporated into French INDOCHINA.
After independence, opposition groups continued to demand further political and social reforms, although the Cambodian offshoot of Ho Chi Minh's Indochina Communist party withdrew its cadres to North Vietnam in 1954 following the Geneva cease-fire agreements for Indochina, Sihanouk gave up the throne to his father in 1955, but he remained a prince, premier, leader of the dominant political movement (the Sangkum), and, after 1960, elected head of state.
In January 1979, following violent disputes with Vietnam over boundaries and revolutionary leadership, Phnom Penh was overrun by the Vietnamese army. Khmer Rouge defectors headed by HENG SAMRIN established a Vietnamese-style people's republic backed by the authority of up to 180,000 Vietnamese troops and myriad advisors. The Khmer Rouge forces staggered to the western boundary with Thailand, where the United Nations eventually organized camps for further waves of Cambodians variously seeking food, haven, or resettlement.
Theravada Buddhism has been the religion of almost all Khmer since the 13th century, when it replaced animism and ancestor worship among the peasants and Brahmanic beliefs at the royal court. The Khmer Rouge banned all religions, disrobed and punished thousands of monks, and desecrated hundreds of temples and monasteries. Buddhism, legally practiced since 1979, again became the official religion in 1989. Monasteries are being restored with government support. The greatest monuments of Khmer culture are the ruins of Angkor Wat and Angkor Thom, which were inspired by a Hinduized worldview and indigenous sculptural idioms.