January -- During his State of the Union Address, President Bush labels Iraq, Iran and North Korea members of an "Axis of Evil" intent on the development and proliferation of weapons of mass destruction.

November - U.N. weapons inspectors return to Iraq, backed by a Security Council resolution.

March 17 - Based on intelligence, later found to be faulty, claiming Saddam harbors weapons of mass destruction, President George W. Bush gives the dictator two days to leave Iraq or face a military invasion.

March 20 - The war in Iraq begins as U.S. forces bomb the capital Baghdad. Ground troops follow days later.

April 9 - U.S.-led forces take control of Baghdad.

April 23 - The Coalition Provisional Authority, an organization installed by the U.S. military, is created to help rebuild the government and infrastructure of Iraq. By May, the CPA is run by L. Paul Bremer until the organization is dissolved in June 2004.

May 1 - President Bush announces the end of major combat operations in Iraq in a speech on the aircraft carrier USS Abraham Lincoln.

August - Insurgency begins with attacks at the Jordanian embassy and U.N. headquarters in Baghdad and a car bomb explosion in Najaf, which kills 125 Iraqis.

Dec. 14 - Saddam, who fled the capital during the U.S.-led invasion, is captured in his ancestral home of Tikrit.

March -- The insurgency grows as attacks in Karbala and Baghdad kill hundreds while U.S. forces lay siege to the Sunni Muslim city of Fallujah.

April - Reports of prisoner abuse at the Iraqi prison Abu Ghraib are leaked to CBS News and the New Yorker magazine.

Jan. 30 - Iraqis vote for representation in the National Assembly. The United Iraqi Alliance, a coalition of mostly Shiite political groups, wins a majority of seats.

April - Kurdish leader Jalal Talabani is elected president by the newly formed Iraqi parliament.

September - Saddam stands trial for crimes against humanity.

Feb. 22 - Bomb attacks on the revered Shiite Golden Mosque in Samarra lead to reprisal killings and sectarian polarization.

April - Talabani asks Nouri al-Maliki to form a new coalition government in Iraq as prime minister.

May/June - The United Nations releases estimates that 100 Iraqi civilians are dying each day from insurgent attacks.

June 7 - Al-Qaida in Iraq leader Abu Musab al-Zarqawi is killed in an air strike.

Nov. 22-24 - More than 200 Iraqis die in a series of car bombs in Sadr City, which rank among the most deadly attacks since the Shiite-Sunni insurgent battles began. These attacks lead some to say the country has descended into civil war.

Iraq re-establishes diplomatic relations with Syria, more than 20 years after severing them during the Iran-Iraq War.

Dec. 30 - Saddam Hussein is executed by hanging nearly two months after his conviction in an Iraqi court for his role in the killing of 148 Shiites in the town of Dujail in the 1980s.

Jan. 26 - Senate confirms Army Lt. Gen. David Petraeus to lead U.S. troops in Iraq.

Spring - Under a new Iraq strategy, 20,000 additional U.S. troops are sent to Iraq to try to quell the violence.

June 13 - Militants again attack a Shiite shrine in Samarra, sparking fears of more reprisal violence.

August - Anti-U.S. cleric Muqtada al-Sadr issues a six-month cease-fire order to his Shiite militia.

October - Iraqi and U.S. troop deaths drop to one of their lowest levels since the start of the war, marking the beginning of a general decline in violence.

Jan. 12 - Iraqi Parliament passes a "reconciliation" law to allow thousands of members of Saddam Hussein's Baath Party to reclaim government jobs and collect pensions.

Feb. 22 - Shiite cleric Muqtada al-Sadr extends his Mahdi Army's cease-fire for another six months.

March 19 - Iraq's presidential council approves a provincial powers law, helping pave the way for local elections in October.

March 25 - Iraqi security forces launch an offensive against Muqtada al-Sadr's Mahdi fighters in the port city of Basra. The city had become the scene of turf wars among local groups seeking control of the oil-rich area. U.S. forces support the Iraqi government's crackdown with airstrikes, and al-Sadr orders his militia to stand down within days.

July - Iraqi officials and President Bush talk of setting a "time horizon" for the withdrawal of U.S. forces in Iraq as part of a broader, long-term security agreement, marking a shift in U.S. policy.

August - Al-Sadr extends his Mahdi Army's cease-fire indefinitely.

Nov. 27 - Iraq's parliament approves a security pact with the United States that outlines the withdrawal of U.S. troops by the end of 2011.

Jan. 21 - The day after taking office, President Obama met with top military officials about the situation in Iraq and the possibility of removing combat troops earlier than the 2011 deadline in the security pact.

June 30 - U.S. combat troops depart Iraqi cities, and the soldiers who remain are designated to coordinate, train and advise Iraqi security forces at their request, according to the terms of the Status of Forces Agreement.