The short answer
The Paris Peace Agreements of 23 October 1991 ended Cambodia’s internationalised conflict and authorised an unusually broad UN transition. UNTAC supported refugee return and organised the 1993 election, after which a new constitution restored the monarchy.
Chronology
A timeline of the turning points
A new government takes Phnom Penh
Vietnamese-led forces removed Democratic Kampuchea, but the conflict continued internationally and near the border.
Negotiations accelerate
Cambodian factions, regional governments and major powers explored withdrawal and a comprehensive settlement.
Vietnam completes troop withdrawal
Vietnam announced the departure of its remaining forces from Cambodia.
A ceasefire takes effect
The Cambodian parties accepted a pause in hostilities while the final agreement was negotiated.
Paris Peace Agreements are signed
Cambodia’s factions and eighteen other states signed instruments for settlement, sovereignty and reconstruction.
UNTAC is established
UN Security Council Resolution 745 authorised the transitional authority.
Refugees return and voters register
UN agencies helped repatriate hundreds of thousands while UNTAC prepared the election.
Constituent Assembly election
Nearly ninety percent of registered voters participated despite intimidation and incomplete disarmament.
A new constitution is promulgated
Cambodia became a constitutional monarchy and UNTAC’s mandate ended.
Why did the conflict continue after 1979?
Vietnamese intervention removed Democratic Kampuchea from Phnom Penh, but the new People’s Republic of Kampuchea lacked broad international recognition. Khmer Rouge, royalist and non-communist forces operated along the Thai border while Cold War rivals supported opposing sides.
Cambodian civilians remained displaced and conflict continued through the 1980s. A durable settlement required agreement among Cambodian factions as well as Vietnam, ASEAN states, China, the Soviet Union, the United States and France.
What did the Paris agreements establish?
Signed on 23 October 1991, the settlement contained separate instruments on a comprehensive political solution, sovereignty and rehabilitation. Cambodia’s Supreme National Council served as the unique legitimate body during the transition.
The United Nations received unusually broad responsibilities over elections, civil administration, security, human rights, refugee return and coordination of international assistance. The agreements nevertheless depended on cooperation from Cambodian parties that was never complete.
What did UNTAC do?
UNTAC deployed civilian, military and police personnel, registered voters, supervised aspects of administration and organised the May 1993 election. UNHCR supported the return of hundreds of thousands of refugees and displaced people.
The mission did not fully disarm the factions, and the Khmer Rouge withdrew from the electoral process. Violence and intimidation persisted, showing that a large international mandate could create political space without exercising complete control.
How did the 1993 election reshape government?
FUNCINPEC won the largest share of seats, ahead of the Cambodian People’s Party. A constitutional crisis and CPP resistance to the result produced a coalition with Prince Norodom Ranariddh and Hun Sen serving as first and second prime ministers.
The constituent assembly adopted a constitution restoring Norodom Sihanouk as king and defining liberal multiparty democracy. UNTAC departed after the new government formed, while the coalition inherited unresolved armed and institutional competition.
What is the peace settlement’s legacy?
The agreements ended Cambodia’s international isolation, enabled refugee return and created the constitutional framework still formally in force. They also made human rights and periodic elections explicit parts of the postwar political order.
Later concentration of power, weakened opposition and incomplete accountability have led to debate about how fully that promise was realised. The settlement remains both a decisive end to internationalised war and a standard against which Cambodian political development is judged.
Continue the chronology
Related history guides
Connected biographies
Four political lives across negotiation and transition
1911—2000
Son Sann
Economist, prime minister and resistance leaderA former Cambodian prime minister who led a non-communist resistance front and presided over the assembly that adopted the 1993 constitution.Read biography
1922—2012
Norodom Sihanouk
King, head of state and independence leaderThe king, independence campaigner and head of state whose long public career crossed colonial rule, neutrality, civil war, exile and Cambodia’s restored monarchy.Read biography
1952—
Hun Sen
Former prime minister and president of the SenateThe politician who became prime minister in 1985, dominated postwar Cambodian politics and transferred the premiership to his son in 2023.Read biography
1953—
Norodom Sihamoni
King of CambodiaThe dancer, teacher and cultural diplomat elected king in 2004, bringing an artistic career to Cambodia’s constitutional monarchy.Read biographyQuick answers
Common questions
- When were the Paris Peace Agreements signed?
- They were signed in Paris on 23 October 1991 by Cambodia and eighteen other participating states.
- What does UNTAC stand for?
- UNTAC is the United Nations Transitional Authority in Cambodia, established by Security Council Resolution 745 on 28 February 1992.
- When was Cambodia’s UN-organised election?
- Voting for a constituent assembly took place from 23 to 28 May 1993.
- Did every faction disarm?
- No. Demobilisation remained incomplete, and the Khmer Rouge withdrew from the process and boycotted the election.
- When was the Cambodian monarchy restored?
- The new constitution was promulgated on 24 September 1993 and restored Norodom Sihanouk as king of a constitutional monarchy.
Primary and institutional sources
How this history was checked
Dates, legal milestones and historical claims are checked against the official and institutional records below. This article was reviewed on 9 September 2026.