On April 17, 1975 the Khmer Rouge captured Phnom Penh.
Former Khmer Rouge leader Pol Pot gave a figure of 800,000, and his deputy, Khieu Samphan, said 1 million had been killed.
After four years of rule, the Khmer Rouge regime was removed from power in 1979 as a result of an invasion by the Socialist Republic of Vietnam and was replaced by moderate, pro-Vietnamese Communists.
At the same time, the Khmer Rouge retreated west, and it continued to control an area near the Thai border for the next decade.
The exact number of people who died as a result of the Khmer Rouge's policies is debated, as is the cause of death among those who died.
One thing is evident, however: the North Vietnamese Communists helped the movement grow by providing political and military support, but became bitter rivals upon the success of Khmer Rouge.
The Khmer Rouge attempted to turn Cambodia into a classless society by depopulating cities and forcing the urban population ("New People") into agricultural communes.
Today, examples of the torture methods used by the Khmer Rouge can be seen at the Tuol Sleng Genocide Museum.
Cambodians were expected to produce three tons of rice per hectare; before the Khmer Rouge era, the average was only one ton per hectare.
On December 29, 1998, the remaining leaders of the Khmer Rouge apologized for the 1970s genocide.
In 1968, the Khmer Rouge forces launched a national insurgency across Cambodia (see also Cambodian Civil War).
The political appeal of the Khmer Rouge was increased as a result of the situation created by the removal of Sihanouk as head of state in 1970.
The leadership of the Khmer Rouge remained largely unchanged from the 1960s to the mid-1990s.
Many people in Cambodia who helped the Khmer Rouge against the Lon Nol government thought they were fighting for the restoration of Sihanouk.
In 1992, however, the Khmer Rouge resumed fighting, boycotted the election and, in the following year, rejected its results.
When the United States Congress suspended aid to Cambodia in 1973, the Khmer Rouge made sweeping gains in the country.
Already in 1981, the Khmer Rouge went as far as to officially renounce Communism and somewhat moved their ideological emphasis to nationalism and anti-Vietnamese rhetoric instead.
By the 1970s, the ideology of the Khmer Rouge combined its own ideas with the anti-colonialist ideas of the PCF, which its leaders had acquired during their education in French universities in the 1950s.
During the rule of the Khmer Rouge, these usages were abolished.
Members of this younger generation may know of the Khmer Rouge only through word of mouth from parents and elders.
On April 17, 1950 (25 years to the day before the Khmer Rouge captured Phnom Penh), the first nationwide congress of the Khmer Issarak groups convened, and the United Issarak Front was established.
Modern research has located thousands of mass graves from the Khmer Rouge era all over Cambodia, containing an estimated 1.39 million bodies.
The Khmer Rouge forced people to work for 12 hours non-stop, without adequate rest or food.
Despite a traditional Cambodian fear of Vietnamese domination, defecting Khmer Rouge activists assisted the Vietnamese, and, with Vietnam's approval, became the core of the new puppet government.
The Khmer Rouge was the ruling political party of Cambodia—which it renamed the Democratic Kampuchea—from 1975 to 1979.
Access to the country during Khmer Rouge rule and during Vietnamese rule was very limited.
The Khmer Rouge, still led by Pol Pot, was the strongest of the three rebel groups in the government, and received extensive military aid from China and intelligence from the Thai military.
Most of the surviving Khmer Rouge leaders live in the Pailin area or are hidden in Phnom Penh.
Sihanouk habitually labeled local leftists the Khmer Rouge, a term that later came to signify the party and the state headed by Pol Pot, Ieng Sary, Khieu Samphan, and their associates.