A chronology of key events:
1534 - 1918 - Region is part of the Ottoman Empire.
Iraq timeline - the short version
1534-1918 - Ottoman rule.
1917 - Britain seizes control, creates state of Iraq.
1932 - Independence, followed by coups.
1979 - Saddam Hussein becomes president.
1980-1988 - Iran-Iraq war.
1990 - Iraq invades Kuwait, putting it on a collision course with the international community.
1991 - Iraq subjected to sanctions, weapons inspections and no-fly zones.
2003 - US-led coalition invades, starting years of guerrilla warfare and instability.
1914 - 1918 - World War I.
1917 - Britain seizes Baghdad.
1920 - Britain creates state of Iraq with League of Nations approval.
1920 - Great Iraqi Revolution - rebellion against British rule.
1921 - Faysal, son of Hussein Bin Ali, the Sharif of Mecca, is crowned Iraq's first king.
1932 - Iraq becomes an independent state.
1939-1945 - World War II. Britain re-occupies Iraq.
1958 - The monarchy is overthrown in a military coup led by Brig Abd-al-Karim Qasim and Col Abd-al-Salam Muhammad Arif. Iraq is declared a republic.
1963 - Prime Minister Qasim is ousted in a coup led by the Arab Socialist Baath Party (ASBP). Arif becomes president.
1963 - The Baathist government is overthrown by Arif and a group of officers.
1966 - After Arif is killed in a helicopter crash on 13 April, his elder brother, Maj-Gen Abd-al-Rahman Muhammad Arif, succeeds him as president.
1968 - A Baathist led-coup ousts Arif. Revolution Command Council (RCC) takes charge with Gen Ahmad Hasan al-Bakr as chairman and country's president.Petroleum firm nationalised
1972 - Iraq nationalises the Iraq Petroleum Company (IPC).
Almost one million people died in the conflict; exchanges of war dead continued for years
1974 - Iraq grants limited autonomy to Kurdish region.
1979 - Saddam Hussein succeeds Al-Bakr as president.
1980 - The pro-Iranian Dawah Party claims responsibility for an attack on Deputy Prime Minister, Tariq Aziz, at Mustansiriyah University, Baghdad.Iran-Iraq war
1980-1988 - Iran-Iraq war.
1981 June - Israel attacks an Iraqi nuclear research centre at Tuwaythah near Baghdad.Chemical attack on Kurds
1988 March - Iraq attacks Kurdish town of Halabjah with poison gas, killing thousands.
1990 March - Farzad Bazoft, an Iranian-born journalist with London's Observer newspaper, accused of spying on a military installation, is hanged in Baghdad.Iraq invades Kuwait
1990 - Iraq invades Kuwait, prompting what becomes known as the first Gulf War. A massive US-led military campaign forces Iraq to withdraw in February 1991.
1991 April - Iraq subjected to weapons inspection programme.Rebellion
1991 Mid-March/early April - Southern Shia and northern Kurdish populations - encouraged by Iraq's defeat in Kuwait - rebel, prompting a brutal crackdown.
1991 Gulf War
Iraq's army was crushed in 1991 Gulf War that followed the invasion of Kuwait
1991 April - UN-approved safe-haven established in northern Iraq to protect the Kurds. Iraq ordered to end all military activity in the area.
1992 August - A no-fly zone, which Iraqi planes are not allowed to enter, is set up in southern Iraq, south of latitude 32 degrees north.
1993 June - US forces launch a cruise missile attack on Iraqi intelligence headquarters in Baghdad in retaliation for the attempted assassination of US President George Bush in Kuwait in April.Oil-for-food
1995 April - UNSC Resolution 986 allows the partial resumption of Iraq's oil exports to buy food and medicine (the "oil-for-food programme").
1995 October - Saddam Hussein wins a referendum allowing him to remain president for another seven years.
1996 August - After call for aid from KDP, Iraqi forces launch offensive into northern no-fly zone and capture Irbil.
1996 September - US extends northern limit of southern no-fly zone to latitude 33 degrees north, just south of Baghdad.
1998 October - Iraq ends cooperation with UN Special Commission to Oversee the Destruction of Iraq's Weapons of Mass Destruction (Unscom).Operation Desert Fox
1998 December - After UN staff are evacuated from Baghdad, the US and UK launch a bombing campaign, "Operation Desert Fox", to destroy Iraq's nuclear, chemical and biological weapons programmes.
1999 February - Grand Ayatollah Sayyid Muhammad Sadiq al-Sadr, spiritual leader of the Shia community, is assassinated in Najaf.
1999 December - UNSC Resolution 1284 creates the UN Monitoring, Verification and Inspection Commission (Unmovic) to replace Unscom. Iraq rejects the resolution.
Saddam Hussein's ouster by US forces prompted jubilation among many Iraqis
2001 February - Britain, US carry out bombing raids to try to disable Iraq's air defence network. The bombings have little international support.Weapons inspectors return
2002 September - US President George W Bush tells sceptical world leaders at a UN General to confront the "grave and gathering danger" of Iraq - or stand aside as the US acts. In the same month British Prime Minister Tony Blair publishes a ''dodgy'' dossier on Iraq's military capability.
2002 November - UN weapons inspectors return to Iraq backed by a UN resolution which threatens serious consequences if Iraq is in "material breach" of its terms.
2003 March - Chief weapons inspector Hans Blix reports that Iraq has accelerated its cooperation but says inspectors need more time to verify Iraq's compliance.Saddam ousted
2003 March - UK's ambassador to the UN says the diplomatic process on Iraq has ended; arms inspectors evacuate; US President George W Bush gives Saddam Hussein and his sons 48 hours to leave Iraq or face war.
2003 March - US-led invasion topples Saddam Hussein's government, marks start of years of violent conflict with different groups competing for power.
2003 July - US-appointed Governing Council meets for first time. Commander of US forces says his troops face low-intensity guerrilla-style war.
Saddam's sons Uday and Qusay killed in gun battle in Mosul.Insurgency intensifies
2003 August - Suicide truck bomb wrecks UN headquarters in Baghdad, killing UN envoy Sergio Vieira de Mello.
Car bomb in Najaf kills 125 including Shia leader Ayatollah Mohammed Baqr al-Hakim.
2003 14 December - Saddam Hussein captured in Tikrit.
2004 March - Suicide bombers attack Shia festival-goers in Karbala and Baghdad, killing 140 people.
2004 April-May - Shia militias loyal to radical cleric Moqtada Sadr take on coalition forces.
Hundreds are reported killed in fighting during the month-long US military siege of the Sunni Muslim city of Falluja.
Photographic evidence emerges of abuse of Iraqi prisoners by US troops.Sovereignty and elections
2004 June - US hands sovereignty to interim government headed by Prime Minister Iyad Allawi.
2004 August - Fighting in Najaf between US forces and Shia militia of radical cleric Moqtada Sadr.
2004 November - Major US-led offensive against insurgents in Falluja.
Al-Qaeda in Iraq
Jordanian-born Abu Musab al-Zarqawi made Al-Qaeda in Iraq the most feared insurgent group
2005 30 January - Some 8 million vote in elections for a Transitional National Assembly. 2005 28 February - At least 114 people are killed by a car bomb in Hilla, south of Baghdad, in the worst single such incident since the US-led invasion.
2005 April - Amid escalating violence, parliament selects Kurdish leader Jalal Talabani as president. Ibrahim Jaafari, a Shia, is named as prime minister.
2005 May onwards - Surge in car bombings, bomb explosions and shootings: Iraqi ministries put the civilian death toll for May at 672, up from 364 in April.
2005 June - Massoud Barzani is sworn in as regional president of Iraqi Kurdistan.
2005 August - Draft constitution is endorsed by Shia and Kurdish negotiators, but not by Sunni representatives.
2005 October - Voters approve a new constitution, which aims to create an Islamic federal democracy.
2005 December - Iraqis vote for the first, full-term government and parliament since the US-led invasion.Sectarian violence
2006 February onwards - A bomb attack on an important Shia shrine in Samarra unleashes a wave of sectarian violence in which hundreds of people are killed.
2006 22 April - Newly re-elected President Talabani asks Shia compromise candidate Nouri al-Maliki to form a new government, ending months of deadlock.
Thousands of Iraqis have been killed in sectarian suicide and car bomb attacks
2006 May and June - An average of more than 100 civilians per day are killed in violence in Iraq, the UN says.
2006 7 June - Al-Qaeda leader in Iraq, Abu Musab al-Zarqawi, is killed in an air strike.
2006 November - Iraq and Syria restore diplomatic relations after nearly a quarter century.
More than 200 die in car bombings in the mostly Shia area of Sadr City in Baghdad, in the worst attack on the capital since the US-led invasion of 2003.Saddam executed
2006 December - Saddam Hussein is executed for crimes against humanity.
2007 January - US President Bush announces a new Iraq strategy; thousands more US troops will be dispatched to shore up security in Baghdad.
UN says more than 34,000 civilians were killed in violence during 2006; the figure surpasses official Iraqi estimates threefold.
2007 February - A bomb in Baghdad's Sadriya market kills more than 130 people. It is the worst single bombing since 2003.
2007 March - Insurgents detonate three trucks with toxic chlorine gas in Falluja and Ramadi, injuring hundreds.
2007 April - Bombings in Baghdad kill nearly 200 people in the worst day of violence since a US-led security drive began in the capital in February.
2007 August - Truck and car bombs hit two villages of Yazidi Kurds, killing at least 250 people - the deadliest attack since 2003.
Kurdish and Shia leaders form an alliance to support Prime Minister Maliki's government but fail to bring in Sunni leaders.
Shia holy sites
Shrine of the Imam Ali, one of Shia Islam's holiest places
2007 September - Controversy over private security contractors after Blackwater security guards allegedly fire at civilians in Baghdad, killing 17.
2007 October - The number of violent civilian and military deaths continues to drop, as does the frequency of rocket attacks.
2007 December - Britain hands over security of Basra province to Iraqi forces, effectively marking the end of nearly five years of British control of southern Iraq.
2008 January - Parliament passes legislation allowing former officials from Saddam Hussein's Baath party to return to public life.
2008 March - Iranian President Mahmoud Ahmadinejad visits.
Prime Minister Maliki orders crackdown on militia in Basra, sparking pitched battles with Moqtada Sadr's Mehdi Army. Hundreds are killed.
2008 September - US forces hand over control of the western province of Anbar - once an insurgent and Al-Qaeda stronghold - to the Iraqi government. It is the first Sunni province to be returned to to the Shia-led government.
Iraqi parliament passes provincial elections law. Issue of contested city of Kirkuk is set aside so elections can go ahead elsewhere.Security pact approved
2008 November - Parliament approves a security pact with the United States under which all US troops are due to leave the country by the end of 2011.
The once-influential radical Shia cleric Moqtada al-Sadr withdrew from politics in 2014
2009 January - Iraq takes control of security in Baghdad's fortified Green Zone and assumes more powers over foreign troops based in the country. PM Nouri al-Maliki welcomes the move as Iraq's "day of sovereignty".
2009 March - US President Barack Obama announces withdrawal of most US troops by end of August 2010. Up to 50,000 of 142,000 troops now there will stay on into 2011 to advise Iraqi forces and protect US interests, leaving by end of 2011.
2009 June - US troops withdraw from towns and cities in Iraq, six years after the invasion, having formally handed over security duties to new Iraqi forces.New political groupings
2009 July - New opposition forces make strong gains in elections to the regional parliament of Kurdistan, but the governing KDP and PUK alliance retains a reduced majority. Masoud Barzani (KDP) is re-elected in the presidential election.
2009 October - Two car bombs near the Green Zone in Baghdad kill at least 155 people, in Iraq's deadliest attack since April 2007.
2009 December - The al-Qaeda-linked Islamic State of Iraq claims responsibility for suicide bombings in Baghdad that kill at least 127 people, as well as attacks in August and October that killed 240 people.
Tension flares with Tehran as Iranian troops briefly occupy an oilfield in Iraqi territory.
2010 January - Controversy as candidates with alleged links to Baath Party are banned from March parliamentary polls. A court later lifts the ban, prompting a delay in campaigning.
"Chemical" Ali Hassan al-Majid, a key figure in Saddam Hussein's government, is executed.Inconclusive elections
2010 March - Parliamentary elections. Nine months pass before a new government is approved.
A complex political landscape has come into being since the fall of Saddam Hussein
2010 August - Seven years after the US-led invasion, the last US combat brigade leaves Iraq.
2010 September - Syria and Iraq restore diplomatic ties a year after breaking them off.
2010 October - Church in Baghdad seized by militants. More than 50 people are killed in what is described as the worst single disaster to hit Iraq's Christians in modern times.
2010 November/December - Parliament reconvenes after long delay, re-appoints Jalal Talabani as president and Nouri al-Maliki as prime minister. A new government includes all major factions.
2011 January - Radical Shia cleric Moqtada Sadr returns after four years of self-imposed exile in Iran.
2011 February - Oil exports from Iraqi Kurdistan resume, amid a lengthy dispute between the region and the central government over contracts with foreign firms.
2011 April - Army raids camp of Iranian exiles, killing 34. Government says it will shut Camp Ashraf, home to thousands of members of the People's Mujahedeen of Iran.
2011 August - Violence escalates, with more than 40 apparently co-ordinated nationwide attacks in one day.US pull out
2011 December - US completes troop pull-out.
Unity government faces disarray. Arrest warrant issued for vice-president Tariq al-Hashemi, a leading Sunni politician. Sunni bloc boycotts parliament and cabinet.
2012 - Bomb and gun attacks target Shia areas throughout the year, sparking fears of a new sectarian conflict. Nearly 200 people are killed in January, more than 160 in June, 113 in a single day in July, more than 70 people in August, about 62 in attacks nationwide in September, and at least 35 before and during the Shia mourning month of Muharram in November.
2012 March - Tight security for Arab League summit in Baghdad. It is the first major summit to be held in Iraq since the fall of Saddam Hussein. A wave of pre-summit attacks kills scores of people.
2012 April - Oil exports from Iraqi Kurdistan halted amid row with central government over contracts with foreign firms.
2012 September - Fugitive Vice-President Tariq al-Hashemi is sentenced to be hanged for murder. He sought refuge in Turkey after being accused of running death squads.
2012 November - Iraq cancels a $4.2bn deal to buy arms from Russia because of concerns about alleged corruption within the Iraqi government. The purchase, signed in October, would have made Russia the country's second-largest arms supplier after the US. Moscow was the main arms supplier of to Saddam Hussein.Violence intensifies
2012 December - President Jalal Talabani suffers a stroke. He undergoes treatment in Germany and makes some progress through the winter and spring.
Sunni Muslims stage mass rallies across the country over several months, protesting against what they see as marginalisation by the Shia-led government.
2013 April - Troops storm a Sunni anti-government protest camp in Hawija near Kirkuk, leaving more than 50 dead and prompting outrage and clashes in other towns.
Insurgency intensifies, with levels of violence matching those of 2008. By July the country is described as being yet again in a state of full-blown sectarian war.
2013 July - At least 500 prisoners, mainly senior al-Qaeda members, escape from Taji and Abu Ghraib jails in a mass breakout.
2013 September - Mass killing at Camp Ashraf housing Iranian exiles - members of the People's Mujahedeen Organisation of Iran.
Regional parliamentary elections in Iraqi Kurdistan, won comfortably by Kurdistan Democratic Party.
Series of bombings hits Kurdistan capital Irbil in the first such attack since 2007. Al-Qaeda-affiliated Islamic State of Iraq says it was responding to alleged Iraqi Kurdish support for Kurds fighting jihadists in Syria.
2013 October - Government says October is deadliest month since April 2008, with 900 killed. By the year-end the UN estimates the 2013 death toll of civilians as 7,157 - a dramatic increase in the previous year's figure of 3,238.
2013 December - At least 35 people killed in twin bombing of Baghdad churches on Christmas Day.Islamist surge
2014 January - Islamist fighters infiltrate Fallujah and Ramadi after months of mounting violence in mainly-Sunni Anbar province. Government forces recapture Ramadi but face entrenched rebels in Fallujah.
2014 February - Radical Shia cleric Moqtada al-Sadr announces that he is withdrawing from politics and dissolving his party.
2014 April - Prime Minister Al-Maliki's coalition wins a plurality at first parliamentary election since 2011 withdrawal of US troops, but falls short of a majority.
2014 June-September - Sunni rebels led by the Islamic State of Iraq and the Levant (ISIS) surge out of Anbar Province to seize Iraq's second city of Mosul and other key towns. Tens of thousands flee amid atrocities. Kurdish forces, US and Iran assist government in repelling attacks, US carries out air raids. ISIS renames itself Islamic State, declares a caliphate.
2014 July - Kurdish Region President Massoud Barzani announces plans for an independence referendum this year, given that Iraq is "effectively partitioned".New broad-based government
2014 September - Shia politician Haider al-Abad forms a broad-based government including Sunni Arabs and Kurds. Kurdish leadership agrees to put independence referendum on hold.
US announces new forward strategy against Islamic State, carries out air raids in support of Iraqi Army near Baghdad. International conference in Paris, including ten Sunni Arab states but excluding Iran and Syria, agrees to support strategy.
2014 December - The Iraqi government and the leadership of the Kurdish Region sign a deal on sharing Iraq's oil wealth and military resources, amid hopes that the agreement will help to reunite the country in the face of the common threat represented by Islamic State.
2015 January - The US-led coalition against Islamic State is reported to have launched more than 900 air strikes against militant targets in Iraq since the campaign began.