Timeline of Cambodian History
Every event is based on a cited source. Choose an era to jump to that part of the timeline.
French colonial period
- 1863
Beginning of French Colonial Rule
In 1863, France established control over Cambodia, and the colonial era began.
In 1863, France arrived in Cambodia, beginning a colonial era that lasted about 90 years. Cambodia was made a French protectorate and governed as part of French Indochina. During this period, educational opportunities for Cambodians were very limited: until the 1940s, there was only one high school in the entire country.
- 1930
Founding of the Indochinese Communist Party
Ho Chi Minh founded the Indochinese Communist Party, one of the origins of the later Khmer Rouge.
In 1930, the Vietnamese revolutionary Ho Chi Minh founded the Indochinese Communist Party (ICP). In 1951 the party split into separate national organizations, and the Cambodian branch became the Khmer People's Revolutionary Party. The Khmer Rouge (the Communist Party of Kampuchea), which later took power in Cambodia, grew out of this lineage. A movement born in the colonial era would go on to deeply shape Cambodia's later history.
- 1951
Formation of the Khmer People's Revolutionary Party
The Indochinese Communist Party split into national organizations, and in Cambodia the Khmer People's Revolutionary Party (KPRP) was born.
In 1951, the Indochinese Communist Party was divided into separate organizations for each country. In Cambodia, the Khmer People's Revolutionary Party (KPRP) was formed. This party would later lead to the force known as the Khmer Rouge. At the time, the movement seeking independence from France was growing stronger in Cambodia.
Independence
- 1953
Independence of Cambodia
On November 9, 1953, Cambodia gained independence from France under the leadership of Sihanouk.
On November 9, 1953, Cambodia achieved independence from France under the leadership of Sihanouk. About 90 years of French colonial rule came to an end, and Cambodians began to govern their own country. This date remains an important national holiday in Cambodia, celebrated as Independence Day. After independence, however, Cambodia came under the influence of the Vietnam War, which was intensifying in the surrounding region.
- 1954
Geneva Accords
The Geneva Accords brought a temporary end to the war in Indochina.
In 1954, the Geneva Accords were signed, bringing a temporary halt to the fighting in Indochina, centered on the war between France and Vietnamese independence forces. During this war, guerrilla activity had also spread into Cambodia and Laos. After the accords, most of the leadership of Cambodia's communist party (the Khmer People's Revolutionary Party) moved to Vietnam. The members who stayed in the country formed a group called the Pracheachon (People's Group), which later came to be known as the Khmer Rouge.
- 1960
Secret Congress Forms the Workers' Party of Kampuchea
A secret party congress held in Phnom Penh established the Workers' Party of Kampuchea.
In September 1960, the first communist party congress was held in secret in Phnom Penh. At this congress, the Khmer People's Revolutionary Party changed its name to the Workers' Party of Kampuchea. This organization would become the core of the Khmer Rouge, which later ruled Cambodia. At the time it was still a small organization, and its existence was almost unknown.
- 1963
Pol Pot Becomes Party Secretary
Saloth Sar (later known as Pol Pot) became secretary of the communist party.
In February 1963, Saloth Sar (who later took the name Pol Pot) became secretary — the top leader — of Cambodia's communist party. At the same time, Nuon Chea became deputy secretary. These two men would later become central figures of the Democratic Kampuchea regime. From around this time, the party began preparing its struggle against the government.
- 1966
Communist Armed Struggle Begins
From 1966 to 1968, communist forces began armed struggle in places such as Samlaut.
Between 1966 and 1968, the Communist Party of Kampuchea (CPK) began its armed struggle. Uprisings by local people broke out in places such as Samlaut and Bay Damram. This was the beginning of the armed conflict that would later grow into a civil war engulfing the whole country. From this period, Cambodia's peace slowly began to crumble.
Civil war
- 1970
Lon Nol Coup and Start of the Civil War
In March 1970, Lon Nol ousted Sihanouk and established the Khmer Republic, and the civil war began.
In March 1970, Prime Minister Lon Nol staged a coup, ousting head of state Sihanouk and establishing the Khmer Republic. In May of the same year, the Communist Party of Kampuchea (the Khmer Rouge) began military action against the new government under the banner of GRUNK, the government-in-exile of Sihanouk, who had fled abroad. Cambodia thus plunged into a civil war that lasted about five years. During this war, large quantities of weapons and landmines were brought into the country.
- 1973
Intensive Bombing of Cambodia
In 1973, the bombing of Cambodia by US forces reached its most intense phase, ending on August 15 of that year.
As the Vietnam War spread, Cambodia itself was bombed between 1970 and 1973. The bombing by US forces was at its most intense from January 1973 until it was halted on August 15 of that year (bombing by the Khmer Republic's air force continued until early 1975). Some of the bombs used did not explode and remained in or on the ground, becoming a major cause of the unexploded ordnance (UXO) problem that persists today. Contamination by UXO, including cluster munitions (submunitions), continues to this day, mainly in eastern Cambodia.
Democratic Kampuchea (Khmer Rouge)
- 1975
Forced Labor and Mass Deaths (1975-1979)
Between 1975 and 1979, an estimated 1.5 to 2 million people lost their lives.
During the Democratic Kampuchea era, from April 1975 to January 1979, an estimated 1.5 to 2 million people died. This was roughly one third of Cambodia's population at the time. People fell victim to forced labor, persecution, and execution, and the tragedy became known to the world as the “Killing Fields.” Ethnic minorities such as the Vietnamese and the Cham were also persecuted.
- 1975
Forced Evacuation of the Cities
The Khmer Rouge forcibly relocated about two million residents of the capital to the countryside.
Immediately after the fall of Phnom Penh, from April 18 to 29, 1975, the Khmer Rouge forcibly relocated at least two million residents of the capital to rural areas. Residents of provincial cities such as Siem Reap, Takeo, and Battambang were also relocated by August of the same year. People were driven from their homes and forced into harsh collective labor in the countryside. The cities were left almost empty.
- 1975
Fall of Phnom Penh to the Khmer Rouge
On April 17, 1975, the Khmer Rouge seized Phnom Penh; five years of civil war ended, and at the same moment a new tragedy began.
On the morning of April 17, 1975, the capital Phnom Penh fell to the forces of the Khmer Rouge (the Communist Party of Kampuchea). This ended five years of civil war and the era of foreign intervention and bombing. From that day, however, began the brutal rule of the Khmer Rouge, remembered as lasting “three years, eight months, and twenty days.” Instead of the peace people had longed for, it was the beginning of an era of even greater suffering.
- 1976
Establishment of Democratic Kampuchea
The new constitution of January 5, 1976 renamed the country “Democratic Kampuchea,” and Pol Pot became prime minister in April.
On January 5, 1976, a new constitution gave the country the name “Democratic Kampuchea.” In April of the same year, Sihanouk stepped down as head of state and Pol Pot became prime minister. The regime pursued extreme policies involving the forced relocation of residents and forced labor. More than 200 security centers (detention camps) were set up across the country, and many people were imprisoned.
People's Republic of Kampuchea
- 1979
Massive Landmine Contamination (Including the K5 Belt)
From around 1979 through the 1990s, huge numbers of landmines were laid, mainly along the Thai border.
Cambodia's landmine and UXO problem arose from a series of conflicts that lasted from the mid-1960s to the end of 1998. Enormous numbers of mines were laid, especially in the fighting at the collapse of the Khmer Rouge regime in 1979 and in the battles that continued through the 1980s and 1990s. In the rural northwest bordering Thailand, a minefield known as the K5 mine belt was left behind, one of the densest areas of landmine contamination in the world. More than 65,000 mine/UXO casualties have been recorded since 1979: about 18,800 people were killed, about 45,000 were injured, and 9,087 lost limbs through amputation (totals as published on the HALO Trust page; for the latest cumulative figures from CMVIS, see the statistics page).
- 1979
Vietnamese Forces Capture Phnom Penh
On January 7, 1979, Vietnamese forces captured Phnom Penh, and the Khmer Rouge regime collapsed.
On January 7, 1979, Vietnamese forces captured Phnom Penh, and the Khmer Rouge's Democratic Kampuchea regime collapsed. The brutal rule known as “three years, eight months, and twenty days” was over, but the Khmer Rouge fled toward the Thai border and continued to resist. At the United Nations, a complicated situation arose: from 1979 to 1990, it was the Khmer Rouge side, not the new government in Phnom Penh, that continued to be recognized as Cambodia's official representative. Cambodia's warfare would go on for years to come.
- 1982
Formation of the Tripartite Coalition
The Khmer Rouge formed a coalition with the Sihanouk and Son Sann factions, and the civil war continued.
In 1982, the Khmer Rouge formed a coalition with the forces of Prince Sihanouk and those of the non-communist leader Son Sann. This tripartite coalition kept up its fight against the Vietnamese-backed government in Phnom Penh. Cambodia remained in a state of civil war throughout the 1980s, and still more landmines were laid, mainly along the Thai border.
- 1989
Withdrawal of Vietnamese Forces
Vietnam completely withdrew its forces from Cambodia by September 26, 1989.
Vietnam later confirmed in writing to the United Nations (UNTAC) that it had completely withdrawn its troops, volunteers, and equipment from Cambodia by September 26, 1989. The roughly ten-year presence of Vietnamese forces came to an end, a major step toward peace. However, conflict among the factions inside the country remained, and the fighting was not yet completely over. The international community began working in earnest on a framework for peace in Cambodia.
Peace and UNTAC
- 1991
International Demining Operations Begin
In 1991, the international NGO The HALO Trust began demining operations in Cambodia.
As the peace process moved forward, the international demining NGO The HALO Trust began operations in Cambodia in 1991. It was the start of a long-term effort to remove the vast numbers of landmines left across the country by years of warfare. The HALO Trust has since destroyed more than 328,483 landmines in Cambodia (cumulative total as of the time the page was viewed). Demining continues as work essential to the return of refugees and the restoration of farmland.
- 1991
United Nations Advance Mission in Cambodia (UNAMIC)
Immediately after the signing of the Paris Agreements, the UN advance mission UNAMIC was sent to Cambodia.
In October 1991, immediately after the signing of the Paris Peace Agreements, the UN Security Council established the United Nations Advance Mission in Cambodia (UNAMIC). UNAMIC deployed to Cambodia to help maintain the ceasefire until the full-scale UN operation (UNTAC) began. It was the first step in the UN's direct involvement in implementing peace in Cambodia.
- 1991
Paris Peace Agreements
On October 23, 1991, the agreements on a comprehensive political settlement of the Cambodia conflict were signed in Paris.
On October 23, 1991, the Agreements on a Comprehensive Political Settlement of the Cambodia Conflict (the Paris Peace Agreements) were signed in Paris. Cambodia was represented by the Supreme National Council (SNC), chaired by Sihanouk. The conference was attended by the five permanent members of the UN Security Council, the six ASEAN countries, Australia, Canada, India, Japan, Laos, and Vietnam. The agreements set out a path to end more than 20 years of warfare and to hold elections under UN supervision. It was a historic accord that became the starting point of Cambodia's peacebuilding.
- 1992
Repatriation of 360,000 Refugees
During the UNTAC period, about 360,000 people returned home from refugee camps on the Thai border.
During UNTAC's operation, about 360,000 refugees and displaced persons returned and resettled under the supervision of the Office of the United Nations High Commissioner for Refugees (UNHCR). People who had left their homes during the years of war were finally able to return. But the northwest, bordering Thailand, had been left with especially large numbers of landmines. Clearing them was an essential task if the returnees were to live safely and resume farming.
- 1992
Establishment of UNTAC
On February 28, 1992, Security Council Resolution 745 established UNTAC, which began deploying on March 15.
On February 28, 1992, the UN Security Council, by Resolution 745, established the United Nations Transitional Authority in Cambodia (UNTAC) for a period not to exceed 18 months. UNTAC's deployment formally began on March 15, 1992. Its mandate was very broad: monitoring the ceasefire, verifying the withdrawal of foreign forces, disarming the factions, supervising the administration, protecting human rights, and conducting free and fair elections. It was the first time the United Nations took direct responsibility for governing an independent country.
- 1992
Establishment of the Cambodian Mine Action Centre (CMAC)
In 1992, the Cambodian Mine Action Centre (CMAC), the core of Cambodia's demining effort, was established.
In 1992, the Cambodian Mine Action Centre (CMAC) was established and began demining operations in June of that year. As Cambodia's leading demining organization, CMAC handles survey and land release, mine and UXO clearance, explosive ordnance risk education, training, and research and development. From June 1992 to June 2023, CMAC alone released about 1,616 square kilometers of mine/UXO-contaminated land. By January 2024 it had destroyed 596,168 landmines. Today about 1,700 staff work at its Phnom Penh headquarters, six provincial demining units, and a training center.
- 1993
UN-Supervised General Elections
General elections were held from May 23 to 28, 1993; about 4.27 million people, 89.56% of registered voters, cast ballots.
From May 23 to 28, 1993, elections for a constituent assembly were held under UNTAC's supervision. A total of 4,267,192 people voted, 89.56% of registered voters. Great numbers of people went to the polls, showing their hope for peace. The elections were a major step in Cambodia's journey from an era of warfare toward building a new nation.
Rebuilding the Kingdom
- 1993
New Constitution and Restoration of the Kingdom of Cambodia
In September 1993, a new constitution was adopted and promulgated, restoring the Kingdom of Cambodia as a constitutional monarchy, and Sihanouk was chosen as king.
On September 21, 1993, the constituent assembly adopted a new constitution by a vote of 113 in favor, 5 against, and 2 abstentions. Sihanouk promulgated the constitution, and Cambodia made a fresh start as the Kingdom of Cambodia, a constitutional monarchy committed to independence, sovereignty, peace, neutrality, and non-alignment. On the same day, Sihanouk was elected king by the Council of the Throne. The king appointed Prince Ranariddh of the FUNCINPEC party as First Prime Minister and Hun Sen of the Cambodian People's Party as Second Prime Minister. UNTAC's mandate ended on September 24, 1993, and Cambodia began building its new nation.
- 1997
Cambodia Signs the Anti-Personnel Mine Ban Convention
On December 3, 1997, Cambodia signed the Anti-Personnel Mine Ban Convention (Ottawa Treaty).
On December 3, 1997, Cambodia signed the Anti-Personnel Mine Ban Convention (Ottawa Treaty), which prohibits the use, stockpiling, production, and transfer of anti-personnel mines. For Cambodia, one of the countries most affected by landmines in the world, joining the treaty carried great significance. The treaty obliges each state to destroy its stockpiled mines and to clear the mines buried in its ground. Cambodia would go on to ratify the treaty and put its domestic legislation in place.
- 1999
End of the Khmer Rouge
The fighting ended by late 1998, and by 1999 the Khmer Rouge had ceased to exist.
The Khmer Rouge survived until 1999, but as its leaders surrendered to the government, were arrested, or died, the organization ceased to exist. Official Cambodian government documents likewise record that the series of conflicts that afflicted the country lasted “from the mid-1960s to the end of 1998.” The era of warfare, spanning roughly 30 years from the 1960s, had at last come to an end. But the vast quantities of landmines and unexploded ordnance the wars left behind would go on threatening people's lives.
- 1999
Domestic Law Prohibiting Anti-Personnel Mines
On May 28, 1999, Cambodia's domestic law banning the use of anti-personnel mines came into force.
On May 28, 1999, Cambodia's domestic law prohibiting the use of anti-personnel mines came into force. This is the law that implements the Anti-Personnel Mine Ban Convention (Ottawa Treaty) domestically. It was an important milestone: Cambodia, where so many citizens had fallen victim to landmines, banned them under its own law. The country thus put its domestic framework in place ahead of ratifying the treaty (July 28, 1999).
- 1999
Ratification of the Mine Ban Treaty
Cambodia ratified the Ottawa Treaty on July 28, 1999, and the treaty entered into force for Cambodia on January 1, 2000.
Cambodia ratified the Anti-Personnel Mine Ban Convention (Ottawa Treaty) on July 28, 1999. The treaty entered into force for Cambodia on January 1, 2000, making it a formal State Party. Cambodia thereby took on the obligation, in principle, to clear all anti-personnel mines from its minefields within ten years of entry into force (by January 1, 2010). For Cambodia, one of the most mine-contaminated countries in the world, this was the beginning of an enormous challenge.
Modern era
- 2000
Establishment of the CMAA
In September 2000, Royal Decree No. 177 established the CMAA, completing the framework for overseeing mine action as a whole.
In September 2000, Royal Decree No. 177 established the Cambodian Mine Action and Victim Assistance Authority (CMAA). The CMAA is the government body that regulates, monitors, and coordinates Cambodia's entire mine action sector. Its responsibilities include accrediting clearance operators, drafting the national strategy, managing data, quality control, and coordinating explosive ordnance risk education and victim assistance. This completed the structure in which organizations such as CMAC carry out the actual clearance while the CMAA oversees the sector.
- 2006
Khmer Rouge Tribunal (ECCC) Begins
The Extraordinary Chambers in the Courts of Cambodia (ECCC) tried crimes of the Khmer Rouge era from 2006 to 2022.
The Extraordinary Chambers in the Courts of Cambodia (ECCC) was a court set up to try crimes committed between April 17, 1975 and January 6, 1979; its investigations and trials ran from 2006 to 2022. In August 2014, former senior regime leaders Khieu Samphan and Nuon Chea were convicted of crimes against humanity, and in November 2018 both were also convicted of genocide. The ECCC, a national court supported by the international community, became the first court in the world to convict a former head of state of genocide. Since January 2023 it has moved to a residual phase focused on preserving records and supporting victims, with more than 230,000 court documents made public and archived.
- 2008
Completion of Stockpile Destruction
In 2008, Cambodia reported the completed destruction of its stockpile of 203,671 anti-personnel mines.
In 2008, Cambodia reported that it had completed the destruction of its stockpiled anti-personnel mines, as required by the Ottawa Treaty. A total of 203,671 mines were destroyed. Only a small number of mines were retained for purposes permitted under the treaty. Together with the clearance of mines in the ground, this was a milestone in acting on the promise never to use landmines again.
- 2009
First Article 5 Deadline Extension
In 2009, Cambodia requested an extension of its clearance deadline, and a new deadline of January 1, 2020 was set.
Cambodia's original clearance deadline under the Ottawa Treaty was January 1, 2010. But even after releasing more than 476 million square meters of land between 1992 and 2008 and destroying 814,698 anti-personnel mines, 19,109 anti-tank mines, and 1,740,831 items of unexploded ordnance, the scale of contamination was still enormous. Cambodia therefore submitted an Article 5 extension request on May 11, 2009; it was approved at the Cartagena Summit that year, and the new deadline became January 1, 2020. The episode speaks to both the severity of the landmine problem and the sheer difficulty of clearance work.
- 2011
Cambodia Hosts the 11th Meeting of States Parties
In 2011, Cambodia hosted the 11th Meeting of the States Parties to the Ottawa Treaty.
In December 2011, Cambodia hosted the 11th Meeting of the States Parties (11MSP) to the Anti-Personnel Mine Ban Convention. Cambodia is also the land where the international movement to abolish anti-personnel mines had begun some 20 years earlier, making it a special meeting in which the treaty's conference returned to its origins. That Cambodia, once a country ravaged by landmines, had become the host of an international conference showed the world how far its recovery had come.
- 2017
National Mine Action Strategy 2018-2025 Approved
In December 2017, a national strategy aiming for a Cambodia free of known mines by 2025 was approved.
In December 2017, Cambodia approved the National Mine Action Strategy (NMAS 2018-2025). The strategy set the goal of “a Cambodia free of known mines by 2025.” It replaced the previous National Mine Action Strategy 2010-2019 and was drawn up following a review by an independent body. It is a comprehensive plan that brings together clearance prioritization, explosive ordnance risk education, victim assistance, and more.
- 2019
Second Article 5 Deadline Extension
In 2019, Cambodia requested a further extension of its clearance deadline, which became December 31, 2025.
On March 27, 2019, Cambodia submitted its second Article 5 extension request under the Ottawa Treaty. The request was approved at the Fourth Review Conference that year, and the new deadline became December 31, 2025. Between 2010 and 2018, Cambodia had released more than 577 million square meters of anti-personnel mine contaminated area, exceeding its original targets. Even so, about 890 million square meters of contaminated area remained as of December 2018, and clearance still needed many more years.
- 2024
Sharp Decline in Mine/UXO Casualties
In 2024, mine/UXO casualties fell to 49, a great decline from earlier years.
Since 1979, more than 65,000 mine/UXO casualties have been recorded in Cambodia. Thanks to years of clearance work and explosive ordnance risk education, however, casualties have fallen sharply. In 2024, the Cambodian Mine Action and Victim Assistance Authority (CMAA) recorded 49 casualties. Clearance and education efforts continue today, aiming for the day when casualties reach zero.
- 2025
Third Article 5 Deadline Extension to 2030
In 2025, Cambodia requested a third extension of its clearance deadline, and the new deadline became December 31, 2030.
On April 7, 2025, Cambodia submitted its third Article 5 extension request under the Ottawa Treaty, followed by a revised version on October 16 of the same year. The request was approved at the 22nd Meeting of the States Parties in December 2025, and the new deadline became December 31, 2030. In 2024, Cambodia again released 130 square kilometers of mine-contaminated land through survey and clearance. Meanwhile, a survey of minefields along the Thai border that began in November 2024 was suspended in June 2025 due to the worsening border situation and other factors. The challenge of achieving a mine-free Cambodia continues, with 2030 as the new target.
Sources & references
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- Ref 0007