A chronology of key events
1863 - Cambodia becomes a protectorate of France. French colonial rule lasts for 90 years.
1941 - Prince Norodom Sihanouk becomes king. Cambodia is occupied by Japan during World War II.
1945 - The Japanese occupation ends.
1946 - France re-imposes its protectorate. A new constitution permits Cambodians to form political parties. Communist guerrillas begin an armed campaign against the French.
1953 - Cambodia wins its independence from France. Under King Sihanouk, it becomes the Kingdom of Cambodia.
1955 - Sihanouk abdicates to pursue a political career. His father becomes king and Sihanouk becomes prime minister.
1960 - Sihanouk's father dies. Sihanouk becomes head of state.
1965 - Sihanouk breaks off relations with the US and allows North Vietnamese guerrillas to set up bases in Cambodia in pursuance of their campaign against the US-backed government in South Vietnam.
1969 - The US begins a secret bombing campaign against North Vietnamese forces on Cambodian soil.
1970 - Prime Minister Lon Nol overthrows Sihanouk in coup. He proclaims the Khmer Republic and sends the army to fight the North Vietnamese in Cambodia. Sihanouk - in exile in China - forms a guerrilla movement. Over next few years the Cambodian army loses territory against the North Vietnamese and communist Khmer Rouge guerrillas
Cambodia Year Zero
1975 - Lon Nol is overthrown as the Khmer Rouge led by Pol Pot occupy Phnom Penh. Sihanouk briefly becomes head of state, the country is re-named Kampuchea.
All city dwellers are forcibly moved to the countryside to become agricultural workers. Money becomes worthless, basic freedoms are curtailed and religion is banned. The Khmer Rouge coin the phrase "Year Zero".
Hundreds of thousands of the educated middle-classes are tortured and executed in special centres. Others starve, or die from disease or exhaustion. The total death toll during the next three years is estimated to be at least 1.7 million.
1976 - The country is re-named Democratic Kampuchea. Sihanouk resigns, Khieu Samphan becomes head of state, Pol Pot is prime minister.
1977 - Fighting breaks out with Vietnam.
1978 - Vietnamese forces invade in a lightning assault.
1979 January - The Vietnamese take Phnom Penh. Pol Pot and Khmer Rouge forces flee to the border region with Thailand.
The People's Republic of Kampuchea is established. Many elements of life before the Khmer Rouge take-over are re-established.
1981 - The pro-Vietnamese Kampuchean People's Revolutionary Party wins parliamentary elections. The international community refuses to recognise the new government.
The government-in-exile, which includes the Khmer Rouge and Sihanouk, retains its seat at the United Nations.
1985 - Hun Sen becomes prime minister. Cambodia is plagued by guerrilla warfare. Hundreds of thousands become refugees.
1989 - Vietnamese troops withdraw. Hun Sen tries to attract foreign investment by abandoning socialism. The country is re-named the State of Cambodia. Buddhism is re-established as the state religion.
An uneasy peace
1991 - A peace agreement is signed in Paris. A UN transitional authority shares power temporarily with representatives of the various factions in Cambodia. Sihanouk becomes head of state.
1993 - General election sees the royalist Funcinpec party win the most seats followed by Hun Sen's Cambodian People's Party (CPP).
A three-party coalition is formed with Funcinpec's Prince Norodom Ranariddh as prime minister and Hun Sen as deputy prime minister.
The monarchy is restored, Sihanouk becomes king again. The country is re-named the Kingdom of Cambodia. The government-in-exile loses its seat at the UN.
1994 - Thousands of Khmer Rouge guerrillas surrender in government amnesty.
1996 - Deputy leader of Khmer Rouge Ieng Sary forms a new party and is granted amnesty by Sihanouk.
1997 - Hun Sen mounts a coup against the prime minister, Prince Ranariddh, and replaces him with Ung Huot. The coup attracts international condemnation. The Khmer Rouge put Pol Pot on trial and sentence him to life imprisonment.
1998 - Prince Ranariddh is tried in his absence and found guilty of arms smuggling, but is then pardoned by the king.
1998 April - Pol Pot dies in his jungle hideout.
1998 July - Elections are won by Hun Sen's CPP, amid allegations of harassment. A coalition is formed between the CPP and Funcinpec. Hun Sen becomes prime minister, Ranariddh is president of the National Assembly.
2001 - A law setting up a tribunal to bring genocide charges against Khmer Rouge leaders is passed. International donors, encouraged by reform efforts, pledge $560 million in aid.
2001 June - US-based Cambodian Freedom Fighters (CFF) members convicted of 2000 attack in Phnom Penh. Group pledges to continue campaign to overthrow Hun Sen.
2001 December - First bridge across the Mekong River opens, linking east and west Cambodia.
2002 -First multi-party local elections; ruling Cambodian People's Party wins in all but 23 out of 1,620 communes. Ranariddh's half-brother Prince Norodom Chakrapong sets up his own Norodom Chakrapong Khmer Soul Party.
2003 - Serious diplomatic upset with Thailand over comments attributed to a Thai TV star that the Angkor Wat temple complex was stolen from Thailand. Angry crowds attack the Thai embassy in Phnom Penh. Hun Sen's Cambodian People's Party wins general elections but fails to secure sufficient majority to govern alone.
Hun Sen re-elected
2004 - After nearly a year of political deadlock, Prime Minister Hun Sen is re-elected after CPP strikes a deal with the royalist Funcinpec party. Parliament ratifies kingdom's entry into World Trade Organisation (WTO). King Sihanouk abdicates and is succeeded by his son Norodom Sihamoni.
2005 February - Opposition leader Sam Rainsy goes abroad after parliament strips him of immunity from prosecution, leaving him open to defamation charges brought by the ruling coalition.
2005 April - Tribunal to try Khmer Rouge leaders gets green light from UN after years of debate about funding.
2005 December - Rainsy is convicted in absentia of defaming Hun Sen and is sentenced to 18 months in prison
2006 February - Rainsy receives a royal pardon and returns home.
2006 May - Parliament votes to abolish prison terms for defamation.
2006 July - Ta Mok, one of the top leaders of the Khmer Rouge regime, dies aged 80.
2006 November - Funcinpec party, a junior partner in the ruling coalition, drops Prince Norodom Ranariddh as its leader.
Khmer Rouge trials
2007 March - Ranariddh is sentenced in absentia to 18 months in prison for selling the Funcinpec party's headquarters - a charge he denies.
2007 July - UN-backed tribunals begin questioning Khmer Rouge suspects about allegations of genocide.
2007 September - Most senior surviving Khmer Rouge member, Nuon Chea - "Brother Number Two" - is arrested and charged with crimes against humanity.
2008 April - US court convicts CFF leader Chhun Yasith of masterminding 2000 attack in Phnom Penh.
2008 July - Hun Sen's ruling CPP claims victory in parliamentary elections criticised by EU monitors. Cambodia and Thailand move troops to disputed land near Preah Vihear temple after decision to list it as UN World Heritage Site fans nationalist sentiment on both sides.
2008 October - Two Cambodian soldiers die in an exchange of fire with Thai troops in the disputed area. Thai soldier dies later of wounds.
New spat with Thailand
2009 - Former Khmer Rouge leader Kaing Guek Eav known as Duch goes on trial on charges of presiding over the murder and torture of thousands of people as head of the notorious Tuol Sleng prison camp.
Parliament again strips opposition leader Sam Rainsy of immunity. He is charged but fails to appear in court.
Another row with Thailand, after Cambodia refuses to extradite ex-Thai prime minister Thaksin Shinawatra and appoints him as an economic adviser instead.
2010 - Comrade Duch is found guilty of crimes against humanity and given 35-year prison sentence.
Diplomatic ties with Thailand resumed after Cambodian government announces resignation of Thaksin Shinawatra.
Exiled opposition leader Sam Rainsy is sentenced in absentia to 10 years in jail after being found guilty of manipulating a map to suggest Cambodia is losing land to Vietnam.
2011 - Tensions rise as Cambodia charges two Thai citizens with spying after they were arrested for crossing the disputed border. Respective forces exchange fire across the border. Hun Sen calls for UN peacekeepers.
Three most senior surviving Khmer Rouge members, including leader Pol Pot's right-hand man, "Brother Number Two" Nuon Chea, go on trial on charges of genocide and crimes against humanity.
Cambodia and Thailand agree to withdraw troops from disputed area.
2012 February - Duch loses appeal against conviction at UN-backed tribunal and has sentence increased to life.
2012 March - A second judge quits the tribunal. Swiss Judge Laurent Kasper-Ansermet says going because his Cambodian counterpart, You Bunleng, had thwarted attempts to investigate some former members of the Khmer Rouge regime.
2012 April - Outspoken environmental activist Chut Wutty is shot dead in a confrontation with police while travelling in a threatened forest region in the south-west.
2012 May - Government suspends the granting of land for development by private companies in a bid to curb evictions and illegal logging.
Border tension eases
2012 July - Cambodia and Thailand withdraw their troops from a disputed border area near the Preah Vihear temple in line with a ruling by the International Court of Justice which aims to halt outbreaks of armed conflict in recent years.
2012 October - Former king, Norodom Sihanouk, dies of a heart attack. He was 89.
2012 November - Government approves the controversial Lower Sesan 2 hydroelectric dam project on a tributary of the Mekong.
2013 February - Tens of thousands of people turn out in Phnom Penh for the cremation of the former king, Norodom Sihanouk.
2013 March - Former Khmer Rouge foreign minister Ieng Sary dies while awaiting trial for genocide, leaving only Nuon Chea and Khieu Samphan among prominent Khmer Rouge figures still alive and under arrest by the UN-backed tribunal.
2013 June - Parliament passes a bill making it illegal to deny that atrocities were committed by the Khmer Rouge in the 1970s.
2013 July - Opposition leader Sam Rainsy returns from exile.
Parliamentary elections. Ruling party of premier Hun Sen claims victory, opposition alleges widespread irregularities.
2013 September - Mass protests in Phnom Penh over contested election results. Parliament approves new five-year term for Hun Sen. Opposition boycotts opening of parliament.
2014 January - Riot police clear a two-week opposition protest camp held in Phnom Penh as part of a long-running campaign launched against the government after the disputed 2013 election.
2014 July - More than 150,000 Cambodian workers return home from neighbouring Thailand after rumours circulate that the new military junta there will crack down on illegal migrants.
Opposition Cambodia National Rescue Party (CNRP) agrees to end its year-long boycott of parliament as part of an agreement with Prime Minister Hun Sen to break the deadlock over the disputed 2013 parliamentary election.
2014 August - A UN-backed court in Cambodia sentences two senior Khmer Rouge leaders to life in prison for their role in the terror that swept the country in the 1970s. The two, second-in-command Nuon Chea, and the former head of state Khieu Samphan, are the first top Khmer Rouge figures to be jailed.
2015 January - Prime Minister Hun Sen marks 30 years in power.
2015 March - A UN-backed tribunal in Cambodia indicts two more former commanders of the Khmer Rouge, Im Cheam and Meas Muth, with crimes against humanity.
2016 July - Kem Ley, a political commentator and prominent critic of Prime Minister Hun Sen is shot dead in the capital Phnom Penh.
2016 September - Prime Minister Hun Sen declares a political "ceasefire" following a wave of prosecutions of opposition members ahead of elections in 2018.
2016 October - Opposition Cambodian National Rescue Party (CNRP) resumes its months-long parliamentary boycott over alleged threats from the ruling party.
2016 November - A UN-backed tribunal upholds the life sentences of former Khmer Rouge leaders Nuon Chea and Khieu Samphan after they appealed against their convictions. for crimes against humanity.
2016 December - Exiled opposition leader Sam Rainsy is sentenced to five years in prison after a document is published on his Facebook page which the government says is a forgery. Mr Rainsy was found guilty of posting an inaccurate post about a border treaty between Cambodia and Vietnam.
2017 February - Sam Rainsy resigns as head of the Cambodia National Rescue Party (CNRP). He had been in self-imposed exile since 2005, when parliament stripped him of his immunity.
Parliament amends a law to bar anyone convicted of an offence from running for office. The legislation in effect bans main opposition politician Sam Rainsy from participating politics after he was found guilty of defamation.
2017 March - Human rights activist Kem Sokha is appointed as the new leader of the opposition Cambodia National Rescue Party (CNRP), replacing Sam Rainsy.
2017 September - Opposition leader Kem Sokha is charged with treason.
2017 November - Supreme Court dissolves the Cambodia National Rescue Party, the country's only significant opposition party.
2018 February - Cambodia introduces lese-majeste law, which makes it a criminal offence to defame or insult the king.