Khmer

The Khmer are an Austroasiatic people of the lower Mekong basin and one of Southeast Asia's oldest settled populations, rice-farming ancestors reaching it by the early second millennium BCE. They built the port kingdom of Funan and successor Chenla, and in 802 Jayavarman II founded the Khmer Empire, the Angkor period.

From hydraulic cities north of the Tonlé Sap, Angkor grew into the world's largest pre-industrial urban complex. Suryavarman II raised Angkor Wat in the early twelfth century; Jayavarman VII added walled Angkor Thom and the Bayon around 1200. Hinduism and Mahayana Buddhism gradually gave way to Theravada Buddhism from the late thirteenth century.

In 1337 the empire was past its peak, weakened by drought, failing waterworks and Siamese wars; in 1431 Ayutthaya sacked Angkor and the court moved to Longvek and then Oudong. Longvek fell to Siam in 1594, and in the seventeenth and eighteenth centuries Vietnamese settlement of the Mekong Delta detached the lower Khmer, or Khmer Krom, lands from the Cambodian heartland.