On April 17, 1975, the Communist Party of Kampuchea, known as the Khmer Rouge, took control of Cambodia after five years of civil war. Led by Saloth Sar, who used the revolutionary name Pol Pot, the party immediately began implementing radical policies designed to transform Cambodia into a self-sufficient agricultural society. The leaders called this new beginning "Year Zero."
Within days of victory, the Khmer Rouge evacuated all cities and towns, forcing millions of people into the countryside to work in agricultural cooperatives. The party abolished money, private property, markets, schools, and religious practices. Families were separated. Traditional Khmer culture faced systematic destruction. The leaders kept their identities secret, referring to themselves only as "Angkar Padevat" (the Revolutionary Organization).
The Khmer Rouge based their vision on an extreme interpretation of Maoist communism combined with Cambodian nationalism. They believed they could recreate the glory of the Angkor period through collective rice production. The party classified people into categories based on their backgrounds and loyalty. Former soldiers, civil servants, teachers, and others considered "class enemies" faced execution. As internal suspicions grew, the regime turned against its own members in widespread purges.
The Communist Party operated an extensive security apparatus. S-21 prison in Phnom Penh served as the central interrogation and execution center, processing approximately 14,000 prisoners. District and village-level security centers operated throughout the country. Researchers have documented over 20,000 mass grave sites from this period.
Life under the regime proved devastating. People worked twelve to fifteen hours daily on inadequate rations. Hundreds of thousands died from starvation, disease, exhaustion, and execution. The regime destroyed or repurposed schools, temples, and cultural institutions. An estimated 90 percent of artists, musicians, and dancers perished. The death toll reached approximately 1.7 to 2 million people out of a population of about 7 million.
Relations with Vietnam deteriorated over border disputes and ideological differences. In December 1978, Vietnamese forces invaded Cambodia. They captured Phnom Penh on January 7, 1979. Khmer Rouge leaders fled westward and continued guerrilla warfare for nearly two decades. The regime retained Cambodia's United Nations seat until 1991, despite international knowledge of its crimes.
The legacy of this period continues to shape Cambodia today. The Documentation Center of Cambodia preserves evidence of the atrocities. The Extraordinary Chambers in the Courts of Cambodia, established in 2006, prosecuted surviving senior leaders. The country still works to recover from the massive loss of life, the destruction of institutions, and the trauma experienced by survivors and their descendants.