As Khmer Rouge forces encircled the capital, the United States conducted an emergency helicopter evacuation from Phnom Penh, signaling the imminent collapse of the Khmer Republic government.
Khmer Rouge forces entered Phnom Penh, ending the Cambodian Civil War and beginning the rule of Democratic Kampuchea. The takeover marked the start of radical social engineering policies and mass violence.
Immediately after taking the capital, the Khmer Rouge ordered the mass evacuation of Phnom Penh (and other urban areas), driving residents into rural labor regimes; the displacement was central to the regime’s attempt to build an agrarian revolutionary state.
With the new regime in control, Cambodia’s central bank was closed and the monetary/banking system was eliminated—one of the Khmer Rouge’s most extreme economic measures aimed at dismantling market life.
The former Tuol Svay Prey school compound in Phnom Penh operated as the S-21 security prison and interrogation center, a key node in the Khmer Rouge’s system of detention, torture, coerced confessions, and execution.
The Communist Party of Kampuchea promulgated a constitution for Democratic Kampuchea, formalizing the new state structure while power remained concentrated in the party leadership (often referenced as Angkar).
Democratic Kampuchea held an election for a 250-seat assembly under a single political front, with official results reporting near-universal turnout and total victory for the Khmer Rouge–dominated slate.
Khmer Rouge forces escalated raids and attacks along the Vietnam border, deepening hostilities that would culminate in full-scale war by late 1978.
Khmer Rouge troops massacred civilians in Ba Chúc (An Giang Province), one of the most notorious attacks in the widening Cambodia–Vietnam conflict and a major trigger for Vietnam’s decision to retaliate militarily.
In 1978, the Khmer Rouge carried out sweeping purges in Cambodia’s Eastern Zone, targeting cadres and civilians alleged to be traitors; the violence produced mass casualties and flight of surviving cadres toward Vietnam.
Vietnam invaded Democratic Kampuchea, supporting Cambodian dissidents and rapidly defeating Khmer Rouge conventional forces, setting the stage for the regime’s collapse in Phnom Penh.
Vietnamese and allied Cambodian forces captured Phnom Penh, ending Khmer Rouge rule over the capital and effectively terminating Democratic Kampuchea’s government, though Khmer Rouge forces continued insurgency afterward.
The Paris Peace Agreements established a comprehensive settlement framework for Cambodia after years of war, enabling a major UN role (UNTAC) and elections as part of the transition.
Cambodia and the United Nations signed an agreement creating the Extraordinary Chambers in the Courts of Cambodia (ECCC) to prosecute senior Khmer Rouge leaders and those most responsible for Democratic Kampuchea–era crimes.
The ECCC convicted Kaing Guek Eav (Duch), the head of S-21, for crimes committed at the prison, marking the tribunal’s first completed case and a landmark accountability milestone.
In Case 002/01, the ECCC sentenced senior Khmer Rouge leaders Nuon Chea and Khieu Samphan to life imprisonment for crimes against humanity, including charges tied to forced population movements.
In Case 002/02, the ECCC convicted Nuon Chea and Khieu Samphan of genocide (notably against ethnic Vietnamese, and for Nuon Chea also against Cham Muslims), alongside other international crimes, and imposed life sentences.
Democratic Kampuchea (Khmer Rouge) and the Cambodian Genocide (1975–1979)
