(CNN) -- Here's a look at what you need to know about the history of Iraq since the 1920's.
1920s-1930s 1921 - After the defeat of the Ottoman Empire during World War I, Great Britain gains control of the area. It sets up a government in Mesopotamia and renames the country Iraq.
1924 - The new Constitutional Assembly of Iraq meets to consider the Anglo-Iraq treaty. The treaty would compel Iraq to honor all agreements made by Great Britain previously, including oil concessions. In order to compel Iraq to accept the treaty, Great Britain threatens to withdraw and leave Iraq vulnerable to Saudi Arabia or Turkey. The treaty is ratified.
October 3, 1932 - Iraq becomes an independent nation with Baghdad as its capital, and is admitted to the League of Nations.
1940s March 22, 1945 - Iraq becomes a founding member of the Arab League.
December 21, 1945 - Iraq becomes a member of the United Nations.
1950s-1960s July 14, 1958 - King Faisal is killed in a coup led by Abdul Karim Kassem.
October 1959 - A group, including Saddam Hussein, attacks the motorcade of Abdul Karim Kassem. The assassination attempt fails and most of the attackers are killed. Hussein escapes and flees to Syria.
February 1963 - Kassem is overthrown and executed. The Baath Party assumes control of the government. Hussein returns from Cairo, Egypt. The new Baath government is overthrown before the end of the year.
July 17, 1968 - In a coup, Major General Ahmed Hassan al-Bakr of the Baath party becomes Iraq's new president. Saddam Hussein becomes the secretary and acting deputy chairman of the Revolutionary Command Council.
1970s October 1973 - Iraq fights Israel in the Yom Kippur war.
March 6, 1975 - Saddam Hussein and Shah Mohammed Reza Pahlavi of Iran meet to discuss a treaty. The Algiers Accord is signed by both countries later in the year.
October 1978 - At the Shah's insistence, Hussein expels Ayatollah Ruhollah Khomeini from Iraq, where he has been in exile for 13 years.
February 1979 - The Ayatollah returns to Iran to lead the country, after the ouster of the Shah in January.
July 16, 1979 - Hussein takes over as president of Iraq.
1979 - In response to the Ayatollah's call for the overthrow of the Baathist regime, comprised mostly of Sunni Muslims, President Hussein expels 40,000 Shiite Muslims. Hussein also orders the execution of Ayatollah Mohammed al-Bakr Sadr, an ally of Ayatollah Khomeini.
1980s September 22, 1980 - Iraq launches an air attack against Iran, beginning the Iran-Iraq war. In 1984 and 1986 Iraq is accused of using mustard gas and other chemical weapons against Iran. The war ends in a stalemate in 1988.
March 16, 1988 - Iraq uses poison gas against the Kurdish people in Halabja in Northern Iraq. Thousands of people are believed to have died in the attack.
1990s August 2, 1990 - Iraq invades Kuwait.
January 17, 1991 - Operation Desert Storm begins.
February 28, 1991 - A ceasefire in the Gulf War takes effect.
March 1991 - After the coalition expels Iraq from Kuwait, the U.S. encourages the Kurds to rebel. However, Iraq crushes the rebellion and one million Kurds flee to Turkey.
April 3, 1991 - The U.N. passes Security Council Resolution 687. It establishes UNSCOM.
April 6, 1991 - Iraq accepts SCR 687.
April 18, 1991 - Under the terms of SCR 687, Iraq gives a detailed account of its weapons inventory. It states that it has no biological weapons program.
April 14, 1995 - The U.N. Security Council adopts Resolution 986 establishing the "oil-for-food" program, providing Iraq with the opportunity to sell oil to finance the purchase of humanitarian goods. Iraq does not accept the plan.
May 20, 1996 - Negotiations between the U.N. and Iraq are finalized for the oil-for-food program.
December 10, 1996 - Phase 1 of the oil-for-food program begins with the extraction of Iraqi oil.
March 1997 - The first oil-for-food shipments of medical supplies and food arrive in Iraq.
December 16, 1998 - Great Britain and the United States launch air strikes against Iraq. The attack, called Operation Desert Fox, is in response to Iraq's refusal to cooperate with U.N. weapons inspectors.
2002 January 29, 2002 - U.S. President George W. Bush says in his State of the Union address that Iraq, Iran and North Korea constitute an "axis of evil'' that threatens the United States.
September 16, 2002 - Facing the threat of U.S. air strikes, Iraq unconditionally agrees to the return of United Nations inspectors.
September 19, 2002 - Iraqi Foreign Minister Naji Sabri sends a letter to the U.N. from Saddam Hussein stating that Iraq has no chemical, nuclear or biological weapons.
November 8, 2002 - The U.N. Security Council unanimously adopts Resolution 1441, outlining strict new weapons inspections and threatening "serious consequences" if Iraq fails to comply.
November 13, 2002 - Iraq agrees to comply with U.N. Resolution 1441.
November 27, 2002 - U.N. inspectors begin working in Iraq.
December 7, 2002 - Iraq submits a 12,000 page declaration of former weapons programs and civilian industries with military applications to the United Nations.
2003 January 27, 2003 - Chief inspectors Mohammad ElBaradei and Hans Blix brief the U.N. Security Council on Iraqi compliance with inspections.
March 7, 2003 - Chief inspectors ElBaradei and Blix submit their final reports to the U.N. Security Council.
March 17, 2003 - President George W. Bush issues an ultimatum to President Saddam Hussein and his family, leave Iraq within 48 hours or face military action.
March 19, 2003 - President George W. Bush announces that U.S. and coalition forces have begun military action against Iraq. (This means that military action began the morning of March 20th in Iraq.)
March 20, 2003 - President Hussein speaks on Iraqi TV. He calls the U.S. led coalition attacks - "shameful crimes against Iraq and humanity."
April 9, 2003 - Coalition forces take Baghdad.
May 1, 2003 - Speaking on the aircraft carrier USS Abraham Lincoln, President George W. Bush declares that "major combat operations" in the Iraq war are over, despite some continued fighting.
May 22, 2003 - The United Nations Security Council approves Resolution 1483, lifting sanctions against Iraq and reaffirms the "sovereignty and territorial integrity of Iraq." It also acknowledges the U.S. and Great Britain's right to occupy Iraq. The resolution sets up a U.N. support system to work with the U.S. and Great Britain to facilitate the transition to a government elected by the people of Iraq.
July 22, 2003 - Uday and Qusay Hussein, President Hussein's sons, are killed by U.S. forces.
November 21, 2003 - The oil-for-food program ends. The Coalition Provisional Authority takes responsibility for supplying humanitarian aid to the Iraqi people.
December 13, 2003 - Hussein is captured in a "spider hole" near a hut in Tikrit. His capture is not confirmed until December 14 by the U.S. Defense Department.
2004 March 8, 2004 - Iraqi Governing Council members sign an interim constitution, laying the groundwork for future elections, a permanent constitution and eventually a return to self-rule.
June 1, 2004 - The Iraqi interim government takes over from the U.S.-backed Iraqi Governing Council (the IGC dissolves itself). The new interim government will be in charge of the country after sovereignty is handed over and until national elections for a transitional government are held by the end of January.
June 28, 2004 - The handover of sovereignty to the interim Iraqi government takes place at 10:26 am local time, two days before the June 30th deadline previously announced by the U.S.-led coalition.
June 30, 2004 - The Coalition turns over legal control of Saddam Hussein and 11 other former top Iraqi officials to the interim Iraqi government. They remain, however, in the physical custody of the U.S. for security reasons.
July 1, 2004 - Saddam Hussein makes his first appearance in court. A judge charges him with a variety of crimes that marked his reign, including the invasion of Kuwait and the gassing of the Kurds.
August 2004 - U.S. and Iraqi forces battle insurgents in Najaf. Many insurgents there are followers of Shiite cleric Muqtada al-Sadr.
September 23, 2004 - Ayad Allawi, interim leader of Iraq, speaks before a joint session of Congress while he is in Washington for meetings with President George W. Bush.
November 2004 - U.S. and Iraqi forces battle insurgents in Falluja. About 2,000 insurgents are killed. On November 14, 2004, the U.S. declares Falluja "liberated."
2005 January 30, 2005 - Millions of Iraqis cast ballots in the nation's first free election in half a century. Iraqi expatriates in Australia, the United States, Great Britain, Canada, Denmark, France, Germany, Iran, Jordan, the Netherlands, Sweden, Syria, Turkey and the United Arab Emirates also participate.
April 6 - 7, 2005 - Kurdish leader Jalal Talabani is selected the country's president by the transitional national assembly. The next day he and two vice presidents are sworn in.
October 15, 2005 - Iraqi citizens vote in a national referendum for a draft new Iraqi constitution.
December 15, 2005 - Millions of Iraqis participate in an election to choose a 275-seat Parliament that will serve a four-year term.
2006 February 10, 2006 - The results of the December 2005 election are certified. The United Iraqi Alliance wins 128 seats, the Kurdistan Alliance Party wins 53 seats, the Iraqi Accord Party wins 44 seats and the final 50 seats are split between five other parties.
April 22, 2006 - President Jalal Talabani names Nuri al-Maliki Prime Minister-designate.
May 20, 2006 - The Iraqi Parliament approves Prime Minister Nuri al-Maliki's choices for the Iraqi national unity government. There are 37 cabinet ministers, comprised of representatives from all major parties and all major ethnic and secular groups.
November 5, 2006 - The Iraqi High Tribunal reaches a verdict in the Dujail case. Eight defendants are charged with crimes relating to the murder of 148 Iraqi men in 1982. Former President Hussein is found guilty and sentenced to death by hanging, pending appeal. The other defendants: - Barzan Hassan, Hussein's half-brother and former head of the intelligence agency, sentenced to death by hanging. - Awad Bandar, former chief judge of the Revolutionary Court, sentenced to death by hanging. - Former Vice-President Taha Yassin Ramadan, sentenced to life in prison. - Abdullah Kadhem Ruwaid, sentenced to 15 years in prison. - Ali Dayem Ali, sentenced to 15 years in prison. - Misher Abdullah Ruwaid , sentenced to 15 years in prison. - Mohammed Azzawi Ali, cleared of all charges.
December 30, 2006 - Former Iraqi President Saddam Hussein is hanged a few minutes after 6 am Baghdad time.
2007 January 2, 2007 - The Iraqi government orders an investigation into the conduct of guards at the hanging of Saddam Hussein.
April 16, 2007 - Muqtada al-Sadr orders his ministers to withdraw from the Iraqi government.
May 28, 2007 - U.S. and Iranian envoys meet in Baghdad to discuss stability in Iraq.
August 1, 2007 - A large Sunni Arab block decides to quit the Iraqi government.
September 3, 2007 - Basra is turned over to local authorities after British troops withdraw from their last military base in Iraq, to the airport outside the city.
November 25, 2007 - The Iraqi government expresses desire for U.S. long-term troop presence in exchange for lifting of U.N. sanctions.
2008 January 12, 2008 - The Iraqi government votes to allow former Baathist party members into government positions.
March 3-4, 2008 - Mahmoud Ahmadinejad, president of Iran, visits Iraq for the first time, meeting with both President Talabani and Prime Minister al-Maliki.
November 27, 2008 - The Iraqi Parliament votes 149-35 in favor of an agreement to authorize the presence of U.S. forces in Iraq beyond 2008.
December 4, 2008 - The Iraqi Presidential Council approves a security agreement that paves the way for the U.S. to withdraw completely from Iraq by 2011.
2009 January 1, 2009 - The U.S. military hands over control of Baghdad's "Green Zone" to Iraqi authorities.
June 30, 2009 - U.S. troops pull back from Iraqi cities and towns and Iraqi troops take over the responsibility for security operations. However, U.S. troops remain in the country to continue combat operations and patrols in rural areas.
2010 March 7, 2010 - Iraqi legislative elections are held. The results are announced on March 26th. The Iraqiya coalition, led by former interim Prime Minister Ayad Allawi, wins the most seats in Parliament.
April 25, 2010 - The first commercial flight from Iraq to the United Kingdom in 20 years takes off from Baghdad. Commercial air links were cut after the United Nations imposed sanctions on Iraq for invading Kuwait in 1990.
August 19, 2010 - The last U.S. combat brigade leaves Iraq. Approximately 52,000 U.S. troops remain in the country.
September 1, 2010 - Operation Iraqi Freedom is renamed Operation New Dawn, to reflect the reduced role U.S. troops will play in securing the country.
December 15, 2010 - The U.N. Security Council votes to free Iraq from sanctions that started during the Saddam Hussein era.
2011 February 6, 2011 - Iraq's state television reports that Prime Minister Nuri al-Maliki will not run for a third term when his current one expires in 2014.
April 9, 2011 - Thousands of demonstrators in Baghdad mark the eighth anniversary of the fall of Hussein's regime with a protest against American troop presence there.
December 15, 2011 - American troops lower the flag of command that flies over Baghdad officially ending the U.S. military mission in Iraq.
2012 September 9, 2012 - Fugitive Iraqi vice-president Tariq al-Hashimi is sentenced to death after being found guilty of running a death squad.