Communist Party of Kampuchea in the context of "Cambodian People's Party"

Pol Pot (born Saloth Sâr; 25 May 1925 – 15 April 1998) was a Cambodian politician, revolutionary, and dictator who ruled the communist state of Democratic Kampuchea from 1975 until his overthrow in 1979. During his reign, his administration oversaw mass atrocities and he is widely believed to be one of the most brutal despots in modern world history. Ideologically a Maoist and Khmer ethnonationalist, Pot was a leader of Cambodia's Communist movement, known as the Khmer Rouge, from 1963 to 1997. He served as General Secretary of the Communist Party of Kampuchea from 1963 to 1981, during which Cambodia was converted into a one-party state. Between 1975 and 1979, the Khmer Rouge perpetrated the Cambodian genocide, in which an estimated 1.5–2 million people died—approximately one-quarter of the country's pre-genocide population. In December 1978, Vietnam invaded Cambodia to remove the Khmer Rouge from power. Within two weeks Vietnamese forces occupied most of the country, ending the genocide and establishing a new Cambodian government, with the Khmer Rouge restricted to the rural hinterlands in the western part of the country.

Born to a prosperous farmer in Prek Sbauv, French Cambodia, Pol Pot was educated at some of Cambodia's most elite schools. Arriving in Paris in October 1949 on an academic scholarship, he later joined the French Communist Party in 1951 while studying at École française de radioélectricité. Returning to Cambodia in 1953, he involved himself in the Khmer Viet Minh organisation and its guerrilla war against King Norodom Sihanouk's newly independent government. Following the Khmer Viet Minh's 1954 retreat into North Vietnam, Pol Pot returned to Phnom Penh, working as a teacher while remaining a central member of Cambodia's Marxist–Leninist movement. In 1959, he helped formalise the movement into the Kampuchean Labour Party, which was later renamed the Communist Party of Kampuchea (CPK). To avoid state repression, in 1962 he relocated to a jungle encampment and in 1963 he became the CPK's leader. In 1968, he relaunched the war against Sihanouk's government. After Lon Nol ousted Sihanouk in a 1970 coup, Pol Pot's forces sided with the deposed leader against the new government, which was bolstered by the United States military. Aided by the Viet Cong militia and North Vietnamese troops, Khmer Rouge forces advanced and controlled all of Cambodia by 1975.

Khmer Rouge is the name that was popularly given to members of the Communist Party of Kampuchea (CPK), and by extension to Democratic Kampuchea, which ruled Cambodia between 1975 and 1979. The name was coined in the 1960s by Norodom Sihanouk to describe his country's heterogeneous, communist-led dissidents, with whom he allied after the 1970 Cambodian coup d'état.

The Kampuchea Revolutionary Army was slowly built up in the forests of eastern Cambodia during the late 1960s, supported by the People's Army of Vietnam, the Viet Cong, the Pathet Lao, and the Chinese Communist Party (CCP). Although it originally fought against Sihanouk, the Khmer Rouge changed its position and supported Sihanouk following the CCP's advice after he was overthrown in a 1970 coup d'état by Lon Nol who established the pro-American Khmer Republic. Despite a massive American bombing campaign (Operation Freedom Deal) against them, the Khmer Rouge won the Cambodian Civil War when they captured the Cambodian capital and overthrew the Khmer Republic in 1975. Following their victory, the Khmer Rouge—who were led by Pol Pot, Nuon Chea, Ieng Sary, Son Sen, and Khieu Samphan—immediately set about forcibly evacuating the country's major cities. In 1976, they renamed the country Democratic Kampuchea.

The French protectorate of Cambodia (Khmer: ប្រទេសកម្ពុជាក្រោមអាណាព្យាបាលបារាំង; French: Protectorat français du Cambodge) refers to the Kingdom of Cambodia when it was a French protectorate within French Indochina, a collection of Southeast Asian protectorates within the French colonial empire. The protectorate was established in 1863 when the Cambodian King Norodom requested the establishment of a French protectorate over his country, meanwhile Siam (modern Thailand) renounced suzerainty over Cambodia and officially recognised the French protectorate on Cambodia.

Cambodia was integrated into the French Indochina union in 1887 along with the French colonies and protectorates in Laos and Vietnam (Cochinchina, Annam, and Tonkin). In 1947, Cambodia was granted self-rule within the French Union and had its protectorate status removed in 1949. Cambodia later gained independence. The day was celebrated as Independence Day on 9 November 1953 led by King Sihanouk and continued to rule as the leader of the nation until he was overthrown in 1970 by the US-led Khmer Republic of Lon Nol in a coup d'état before the rise of Angkar and the Khmer Rouge coming to power on 17 April 1975, following the Fall of Phnom Penh and the end of the Cambodian Civil War.

The Kingdom of Cambodia, also known as the First Kingdom of Cambodia, and commonly referred to as the Sangkum period, refers to Norodom Sihanouk's first administration of Cambodia, lasting from the country's independence from France in 1953 to a military coup d'état in 1970. Sihanouk continues to be one of the most controversial figures in Southeast Asia's turbulent and often tragic postwar history. From 1955 until 1970, Sihanouk's Sangkum was the sole legal party in Cambodia. After the 1970 coup, the semi-official name of Cambodia was State of Cambodia, it became a transitional government under a military dictatorship of Prime Minister Lon Nol against the Khmer Rouge and North Vietnamese.

Following the end of World War II, France restored its colonial control over Indochina but faced local resistance against their rule, particularly from Communist guerilla forces. On 9 November 1953, Cambodia achieved independence from France under Norodom Sihanouk but still faced resistance from Communist groups such as United Issarak Front. As the Vietnam War escalated, Cambodia sought to retain its neutrality but in 1965, North Vietnamese soldiers were allowed to set up bases and in 1969, the United States began a bombing campaign against North Vietnamese soldiers in Cambodia. The Cambodian monarchy was abolished in a coup on October 9, 1970 headed by Prime Minister Lon Nol, who established the Khmer Republic which lasted until the Fall of Phnom Penh to the Khmer Rouge led by Angkar ("Organization") when it came to power on 17 April 1975.

Democratic Kampuchea was the official name of the Cambodian state from 1976 to 1979, under the general secretaryship of Pol Pot and the Communist Party of Kampuchea (CPK), commonly known as the Khmer Rouge. The Khmer Rouge's capture of the capital Phnom Penh in 1975 effectively ended the United States-backed Khmer Republic under Prime Minister-later President Lon Nol.

From 1975 to 1979, the Khmer Rouge's one-party regime killed millions of its own people through mass executions, forced labour, and starvation, in an event which has come to be known as the Cambodian genocide. The killings ended when the Khmer Rouge were ousted from Phnom Penh by the People's Army of Vietnam (PAVN). The Khmer Rouge subsequently established a government-in-exile in neighbouring Thailand and retained Kampuchea's seat at the United Nations (UN). In response, Vietnamese-backed communists created a rival government, the People's Republic of Kampuchea, but failed to gain international recognition.

The Cambodian–Vietnamese War was an armed conflict from 1978 to 1989 between the Khmer Rouge and Vietnam, and their respective allies. It began in December 1978, with a Vietnamese invasion of Cambodia which toppled the Khmer Rouge and ended in 1989 with the withdrawal of Vietnamese forces from Cambodia. This Cold War conflict was part of the Third Indochina War and Sino-Soviet split with the Soviet Union supporting Vietnam and China supporting the Khmer Rouge.

Despite both being communist, the alliance between the Communist Party of Vietnam and the Khmer Rouge broke down after both defeated Vietnamese and Cambodian anti-communist regimes respectively in the Vietnam War. As a result, the war was preceded by years of conflict between Vietnam and the Khmer Rouge, led by Pol Pot, when the Khmer Rouge ruled Democratic Kampuchea repeatedly invaded Vietnam, including massacres by the Khmer Rouge, notably the Ba Chúc massacre of over 3,000 Vietnamese civilians in April 1978. On 21 December 1978, the Vietnamese launched a limited offensive towards the town of Kratie. On 23 December 1978, 10 out of 19 divisions of the Khmer Rouge's Kampuchea Revolutionary Army opened fire along the border with Vietnam with the goal of invading the southwestern border provinces of Đồng Tháp, An Giang and Kiên Giang. On 25 December 1978, Vietnam supported Cambodian dissidents in exile and launched a full-scale invasion of Kampuchea, occupying the country in two weeks, capturing the capital Phnom Penh, and removing the Khmer Rouge government of the Communist Party of Kampuchea from power. In doing so, Vietnam put an ultimate stop to the Cambodian genocide which had killed between 1.2 and 2.8 million people or between 13 and 30 percent of the country's population since 1975. However, the Khmer Rouge regime maintained its membership in the United Nations and the war isolated Vietnam from the international community except the Eastern Bloc. The Vietnamese occupation caused discontent among Cambodians.

Year Zero (Khmer: ឆ្នាំសូន្យ, Chhnăm Sony [cʰnam soːn]) is an idea put into practice by Pol Pot in Democratic Kampuchea that all culture and traditions within a society must be completely destroyed or discarded and that a new "revolutionary" culture must replace it starting from scratch. In this sense, all of the history of a nation or a people before Year Zero would be largely deemed irrelevant, because it would ideally be purged and replaced from the ground up.

The first day of "Year Zero" was declared by Angkar and the Khmer Rouge on 17 April 1975 upon their takeover of Cambodia to signify a rebirth of Cambodian history. Adopting the term as an analogy to the "Year One" of the French Revolutionary Calendar, Year Zero was, in effect, an attempt by the Khmer Rouge to erase history and reset Cambodian society, removing any vestiges of the past.

The General Secretary of the Central Committee of the Communist Party of Kampuchea (Khmer: អគ្គលេខាធិការគណៈកម្មាធិការមជ្ឈិមបក្សកុម្មុយនីស្តកម្ពុជា) was the highest office in the Communist Party of Kampuchea (CPK). The General Secretary was elected at plenary sessions of the party's Central Committee, and chaired the Secretariat and Politburo. The office was abolished when the CPK dissolved in 1981, two years after being removed from power in the Vietnamese invasion of Cambodia.