A four-year period cost 1.671 and 1.871 million people from 1975 to 1979 , or 21 to 24 percent of Cambodia 's 1975 population . through the combined result of political executions , disease , starvation , and forced labor . Due to the large numbers , the deaths during the rule of the Khmer Rouge are commonly known as the Cambodian genocide . The Khmer Rouge took power at the end of the Cambodian Civil War and were only toppled after the invasion of Cambodia by the neighbouring Socialist Republic of Vietnam in the Cambodian – Vietnamese War . Most of Cambodia remained under Vietnamese occupation for over a decade
Cambodian genocide
Cambodian genocide
Khmer Rouge rule of Cambodia