The Khmer people originated in what is now called Cambodia in Southeast Asia. Throughout their history they have faced invasions from neighboring countries Vietnam and Thailand, and were colonized by the French in the late 1880s.n 1979 when Pol Pot and the Khmer Rouge were overthrown by the Vietnamese, Khmer people fled in large numbers to refugee camps in nearby countries. The fled because of displacement due to continued fighting, fears of persecution by the Vietnamese, and poverty and starvation due to poor harvests.