BAGHDAD — A timeline of key events in Iraq, beginning with the 2003 U.S.-led invasion up to April 30 national elections. More than 22 million voters will be eligible to cast their ballots to choose 328 lawmakers out of more than 9,000 candidates in the first nationwide elections since the U.S. army withdrawal in 2011.
- March 20: The U.S.-led invasion is launched and Baghdad is attacked with missiles and bombs in a failed attempt to kill Saddam Hussein.
- April 9: American troops storm Baghdad and the statue of Saddam is toppled in Firdous Square in a symbolic collapse of his regime.
- May 1: President George W. Bush declares an end to major combat operations.
- July 22: Saddam's sons Oday and Qusay are killed by gunfire in the northern city of Mosul.
- Aug 7: A car bomb strikes the Jordanian embassy, the first such attack of the war. Twelve days later, a truck bomb demolishes the United Nations headquarters in Baghdad, killing top U.N. envoy Sergio Vieira de Mello and 21 others.
- Aug. 29: Bomb at Najaf Imam Ali shrine kills more than 85 people, including Shiite leader Ayatollah Mohammed Baqir al-Hakim.
- Sep. 3: U.S. announces an Iraqi administration largely made up of Iraqi exiles who opposed Saddam.
- Dec. 13: Saddam is captured in an underground hideout near Tikrit.
- Feb. 1: Two suicide bombers attack Kurdish political offices in Irbil, killing 117 people and injuring 133.
- March 2: Multiple explosions rock Baghdad and Karbala at the climax of a Shiite festival, killing nearly 200 people in the deadliest attack so far.
- March 8: Iraqi Governing Council approves an interim constitution.
- March 31: Four Blackwater security contractors are ambushed and killed in Fallujah, setting off the first battle for the insurgent-dominated city west of Baghdad.
- April 4: Followers of Shiite cleric Muqtada al-Sadr launch attacks across southern Iraq after the U.S. tries to close his newspaper. Fighting rages until the end of August.
- April 18: U.S. announces an investigation into abuses against detainees at the Abu Ghraib prison as gruesome photos emerge showing Iraqi prisoners humiliated.
- May 17: The head of the Iraqi Governing Council, Ezzedine Salim, is killed in suicide attack near the entrance to the Green Zone.
- May 19: U.S. jets mistakenly bomb a wedding party in western Iraq, killing 42 people, including women and children.
- June 28: The U.S. transfers sovereignty to the Iraqis but retains most of the real power. The civilian head of the occupation authority, L. Paul Bremer, leaves the country.
- July 1: Trial of Saddam, with the ousted leader appearing at his first hearing.
- Sept. 30: A car bomb strikes American troops handing out candy to children, killing up to 35 children.
- Oct. 6: U.S. arms inspector finds no evidence Saddam's regime produced weapons of mass destruction.
- Nov. 7: U.S. soldiers and Marines launch the biggest attack of the war to date to seize the insurgent stronghold of Fallujah.
- Dec. 21: A bomb kills 22 people, including 18 Americans, at Forward Operating Base Marez in Mosul.
- Jan. 26: A helicopter crashes in western Iraq, killing 31 Americans.
- Jan. 30: Iraqis select a new parliament in the first elections since the fall of Saddam. Shiite and Kurdish parties take an overwhelming majority after Sunnis largely boycott the vote.
- Feb. 28: A vehicle bomb kills 127 people in Hillah.
- March 4: Italian journalist Giuliana Sgrena is freed by Italian intelligence but the rescuing agent is killed when U.S. troops fire on their vehicle en route to Baghdad airport.
- Aug. 28: An Iraqi commission submits a draft constitution to parliament.
- Aug. 31: Rumors of a suicide bomber panics Shiite marchers in a religious procession at a Baghdad bridge and nearly 1,000 people reportedly die in the stampede.
- Sept. 14: A series of bombings kills 160 people in Baghdad in a dramatic escalation of the insurgency.
- Oct. 15: Iraqis approve the new constitution in a referendum.
- Oct. 24: The Palestine and Sheraton hotels, favored by Western journalists, are struck by multiple truck bombs.
- Nov. 19: U.S. troops kill 24 people, including 15 noncombatants, in Haditha after an insurgent attack.
- Dec. 15: Iraqis choose a new parliament in the first election under the new constitution.
- Feb. 22: Sunni militants bomb the Shiite Golden Dome shrine in Samarra, triggering a wave of sectarian violence that brings Iraq to the brink of civil war.
- May 20: Nouri al-Maliki is sworn in as prime minister.
- June 7: The leader of al-Qaida in Iraq, Abu Musab al-Zarqawi, is killed in a U.S. airstrike northeast of Baghdad.
- June 17: U.S. troops launch a battle to take control of the western city of Ramadi in a bloody conflict that persists for more than a year.
- July 9: Shiite militias kill 40 Sunnis in the Jihad neighborhood of Baghdad as sectarian war spreads to the capital.
- September: First meeting in Anbar of what become known as the Awakening Councils. Set up to fight al-Qaida in Iraq, the groups lead to a drop in violence in later years.
- Nov. 23: Bombs kill more than 200 Shiites in Baghdad's Sadr City neighborhood.
- Dec. 30: Saddam is executed by hanging.
- Jan. 10: President Bush orders 30,000 reinforcements to Iraq in an effort to stem the sectarian war and stabilize Baghdad.
- Jan. 28: Followers of a Shiite cult launch a battle in Najaf that kills nearly 300 people.
- Feb. 3: A bomb in a Baghdad market kills 135 people.
- Feb. 27: Shiite militias besiege British bases in Basra, ultimately prompting most British forces to leave the country.
- March 27: A blast in Tal Afar kills 152 people, setting off a wave of Shiite reprisals that claim 70 Sunni lives.
- April 18: Bombs across Baghdad kill nearly 200 people.
- Aug. 14: A series of bombings directed against the Yazidi religious community in the north kills nearly 800 people.
- Aug. 29: Muqtada al-Sadr announces a cease-fire after a public backlash against his militia following a clash in Karbala that killed 50 people. Attacks against U.S. troops in Shiite areas begin to drop.
- Sept. 16: Blackwater security guards mistakenly believing they were under attack kill 17 civilians in Nisoor Square in Baghdad.
- Jan. 8: U.S. and Iraqi forces launch operations in Baghdad to secure the capital.
- Jan. 23: Operations begin in Mosul against al-Qaida's last major urban stronghold.
- Feb. 21: Turkey launches an offensive in northern Iraq against Kurdish rebels from the PKK.
- March 25: Heavy fighting breaks out in Basra as Iraqi forces try to crush Shiite militias, which launch counterattacks in Baghdad. Fighting rages for a month until a cease-fire is reached.
- Oct. 26: U.S. special operations troops strike in Syria to break up a ring smuggling weapons and fighters into Iraq.
- Nov. 27: The Iraqi parliament approves an agreement with the U.S. calling for the departure of all U.S. troops by the end of 2011.
- Jan. 1: The U.S. hands over control of the Green Zone to Iraqis, opens new American Embassy.
- May 27: The last British combat troops leave Iraq.
- June 30: U.S. troops withdraw from cities.
- Aug. 19: A massive truck bomb kills about 100 people in Baghdad.
- Oct. 25: Bombs targeting government buildings kill 127 in Baghdad.
- Feb. 14: A Shiite-led panel bans hundreds of candidates with suspected ties to Saddam's Baath party from elections.
- March 7: Iraq holds parliamentary elections. The bloc of al-Maliki's challenger, Ayad Allawi, wins largest number of seats but not majority, setting off an eight-month political impasse.
- May 10: Attacks kill at least 100 people, mostly in Shiite areas, in Iraq's bloodiest day of 2010.
- Aug. 19: Last American combat troops leave; 50,000 American soldiers remain to advise Iraqis.
- Oct. 10: Anti-American cleric Muqtada al-Sadr's party backs al-Maliki, boosting his bid to remain in power.
- Nov. 10: Iraqi lawmakers strike deal that would keep al-Maliki as prime minister.
- Nov. 11: Parliament meets, takes first formal step in creating new government by electing speaker.
- Dec. 21: Al-Maliki is sworn in as prime minister for second term.
- April 8: The Iraqi army raids Camp Ashraf, home to Iranian exiles. The raid kills 34 Iranian dissidents and produces calls for the Iraqi government to honor agreements for the protection of the camp.
- Dec. 18: The last American troops leave Iraq.
- Dec. 19: The Shiite-led government issues an arrest warrant against Sunni vice president, Tariq al-Hashemi, accusing him of running a hit squad that assassinated government and security officials. The top Sunni official denies the charges as politically motivated. The day before, al-Hashemi left Baghdad, going first to the self-ruled northern Kurdish region and then abroad.
- Jan. 5: A wave of bombings targeting Shiite Muslims kills at least 78 people in Iraq.
- Mar. 25: Iraq hosts a summit of Arab leaders, held here for the first time in a generation.
- Sep. 9: A Baghdad court sentences Iraq's fugitive Sunni vice president to death in absentia after finding him guilty of masterminding the killings of a lawyer and a government security official. More death sentences followed.
- Nov. 16: Baghdad security forces and Kurdish guards clash for the first time. The standoff was sparked by a police hunt for a smuggler who sought refuge in a Kurdish political party office. A civilian is killed.
- Dec. 18: Iraqi President Jalal Talabani is hospitalized in Baghdad after suffering a stroke. A few days later, Talabani is flown to Germany for medical treatment.
- Dec. 20: Iraqi security forces storm the office of Sunni Finance Minister Rafia al-Issawi and arrest some of his bodyguards, sparking huge protests in the country's Sunni areas.
- Jan. 25: Iraqi troops open fire on stone-throwing Sunni demonstrators in Fallujah, killing at least five protesters — the first fatalities in more than a month of anti-government rallies.
- March 4: At least 48 Syrian soldiers who had sought refuge in western Iraq are ambushed and killed, raising concerns that Iraq might be drawn into Syria's civil war.
- April 23: Iraqi security forces launch a heavy-handed crackdown on a Sunni protest camp in the northern town of Hawija. Forty-four civilians and one policeman were killed.
- Dec. 22: Iraqi security forces start major offensive in Iraq's western desert in Anbar province to chase down al-Qaida-linked militants after killing a senior army commander.
- Dec. 28: Iraqi troops detain Sunni lawmaker, Ahmed al-Alwani, a prominent organizer of the Sunni protests in Anbar. He is sought on terrorism charges for inciting violence against Shiites.
- Dec. 30: Iraqi police take down tents and clear a major Sunni sit-in in Anbar provincial capital, Ramadi, sparking clashes with militants. To alleviate the tension, the army pulls back from major cities, allowing al-Qaida militants to seize control parts of Ramadi and the whole city of Fallujah.
- March 1: Iraq announces its daily oil production has exceeded 3.5 million barrels and that daily exports surged to 2.8 million barrels the previous month, the highest level in the past three decades.
April 30: Iraq holds its third national elections since the U.S.-led invasion that toppled Saddam. The parliament elections are also the first balloting since the 2011 U.S. army withdrawal.