TIMELINE: Key events in the history of al-Qaeda

May 1, 2011: Osama bin Laden, head of al-Qaeda, is killedwhen CIA paramilitaries and a Navy SEAL team attack his compound in Abbottabad, Pakistan.

April 26, 2011: NATO reveals that Abu Hafs al-Najdi, also known as Abdul Ghani, a regional commander in Afghanistan in charge of suicide bombings and cash flow, was killed by an airstrike earlier in the month.

April 25, 2011: TheAl Sunnah Al Nabawiah Mosque in Montrealwas among nine houses of prayer or Islamic institutes worldwide considered by the U.S. military to be places where "known al-Qaeda members were recruited, facilitated or trained," according to leaked classified American intelligence documents.

Nov. 19, 2010: Pervez Musharraf, former president of Pakistan,could not say definitelythat he would have handed over Osama bin Laden to the United States if the al-Qaeda leader had been found in his country.

Nov. 5, 2010: A Yemen-based al-Qaeda group claims responsibility a week after authoritiesintercepted packagesin Dubai and England that were bound for the United States. Both mail bombs were wired to detonators that used cellphone technology and were hidden in the toner cartridges of computer printers, but were intercepted before causing any damage. Al-Qaeda in the Arabian Peninsula issues a message saying it will continue to strike American interests.

Nov. 3, 2010: Al-Qaeda's front group in Iraqthreatens more attacks on Christiansfollowing a bloody siege at a Baghdad church that left 58 people dead, saying the "killing sword will not be lifted" from their necks.

June 1, 2010: Al-Qaeda's No. 3,Sheikh Sa'id al-Yazid, is believed killedby a U.S. Predator drone strike.

April 20, 2010: Two top-ranking al-Qaeda figures,Abu Omar al-Baghdadi and Abu Ayyub al-Masri, are killed in what U.S. Vice-President Joe Biden called a "potentially devastating blow" to al-Qaeda in Iraq.

Jan. 18, 2010:Yemen's foreign minister visits Ottawaseeking support from the government of Canada as the Middle Eastern country struggles with al-Qaeda elements within its borders.

Jan. 13, 2010:Yemeni security forces kill Abdullah Mihzar, a who was on the list of wanted al-Qaeda figures, and arrest four others.

Dec. 25, 2009: A man who admitted to being an al-Qaeda supporter tries toblow up a Northwest Airlines planeas it was preparing to land in Detroit. Travellers who smelled smoke and heard what sounded like firecrackers rushed to subdue him, passengers and federal officials said.

Dec. 24, 2009:Yemen's military hits suspected al-Qaeda hideouts, killing at least 30 militants and targeting a gathering of top leaders in a remote mountain valley, officials said.

July 23, 2009: Osama bin Laden's son Saad is killed in Pakistan by a U.S. missile.

Nov. 19, 2008: Al-Qaeda's second-in-command,Ayman al-Zawahri, criticizes U.S. president-elect Barack Obamain a message, calling him a demeaning racial term implying that he is a black American who does the bidding of whites.

Aug. 6, 2008: Osama bin Laden's former driver,Salim Hamdan, is found guilty on a terrorism chargein the first verdict to come through the controversial U.S. military tribunal process at Guantanamo Bay, Cuba.

April 18, 2008: The second-in-command of al-Qaeda,Ayman al-Zawahiri, said in an audiotapethat five years of involvement in Iraq has brought the U.S. only defeat, and said President Bush will be forced to pass the problem to his successor.

March 19, 2008: A message purporting to be from al-Qaeda leader Osama bin Laden andblasting the publication of cartoons of the Prophet Muhammadis released on the fifth anniversary of the U.S.-led invasion into Iraq. The audio message, directed at the European Union, warns of grave punishments in connection to the cartoons, which were originally published by a Danish newspaper in fall 2005 and sparked weeks of violent demonstrations across the Middle East and Asia.

March 14, 2008: U.S. authorities said they are holding a high-level al-Qaeda figure,Muhammad Rahimal-Afghani, who helped Osama bin Laden escape from Afghanistan.

Nov. 29, 2007: Osama bin Ladencalls on Europeansto stop helping the United States in the war in Afghanistan, according to excerpts of an audiotape broadcast on Al-Jazeera television.

Sept. 11, 2007:Osama bin Laden releases a videotapeon the sixth anniversary of the Sept. 11 attacks, showing one of the suicide hijackers speaking his last will and testament into the camera as his image is superimposed upon an image of a burning World Trade Center.

Sept. 7, 2007: In a video,Osama bin Laden delivers a wandering 30-minute tiradeagainst democracy, capitalism and Western political leaders. He specifically refers to U.S. President George W. Bush, the Democratic victory in U.S. Congress, French President Nicolas Sarkozy, who was elected in May, and new British Prime Minister Gordon Brown, who took office in June.

June 30, 2006: A 19-minute message posted on an Islamic militant website showsOsama bin Laden praising Abu Musab al-Zarqawi, the slain al-Qaeda leader in Iraq, and calling on U.S. President George W. Bush to return Zarqawi's body to his native Jordan.

June 7, 2006:The leader of al-Qaeda in Iraq is killedduring a targeted air strike conducted by U.S. forces northeast of Baghdad in the province of Diyala. The 39-year-old Jordanian-born Abu Musab al-Zarqawi had a $25-million US bounty on his head.

May 3, 2006:Zacarias Moussaoui, the only person charged in the U.S. in connection with the Sept. 11, 2001 attacks, is found guilty of the charges against him. He is sentenced to life imprisonment.

January 2006: Bin Laden addresses comments to the American people rather than U.S. President George W. Bush because, he said, polls showed "an overwhelming majority" of Americans wanted a withdrawal from Iraq. Bin Laden recommends Americans pick up a copy of the book The Rogue State, which he said offered a path to peace.

May 4, 2005: Pakistani security forces announce they have arrested Abu Faraj Farj al-Libbi, the senior al-Qaeda militant suspected of planning two assassination attempts against President Pervez Musharraf. Al-Libbi is a close associate of Osama bin Laden and the head of al-Qaeda operations in Pakistan.

April 22, 2005: The trial of 24 allegedal-Qaeda members opens in Spain. Three of the men are accused of helping plan the Sept. 11, 2001, attacks in the U.S. Zacarias Moussaoui, the so-called "20th hijacker," pleads guilty to all charges against him in connection with the Sept. 11, 2001, attacks.

Jan. 21, 2005: Doubleday announces plans to publish English translations of interviews with Osama bin Laden in 2006 under the tentative title The al-Qaeda Reader.

Dec. 16, 2004: A new audio message thought to be from Osama bin Laden is found on an Islamic website. The audiotape criticizes Saudi Arabia's government for being too close to the United States.

Dec. 6, 2004: The Saudi wing of al-Qaeda claims responsibility for an attack on the American Consulate in Jeddah, Saudi Arabia, that killed five staff members and left four militants dead.

Oct. 29, 2004: In a message broadcast by Al-Jazeera,Osama bin Laden claims direct responsibility for the 2001 attacks against the United States.

Oct. 15, 2004: German authorities arrest Mamoun Darkazanli, a suspected al-Qaeda financier, on a Spanish warrant in Hamburg.

Sept. 26, 2004: Pakistani police shoot and kill Amjad Hussain Farooqi, a top al-Qaeda official, in Nawabshahm, Pakistan. Farooqi was suspected of plotting attacks on the Pakistani president.

Aug. 8, 2004: Qari Saifullah Akhtar, a top-level al-Qaeda member accused of running a training camp in Afghanistan, is arrested in the United Arab Emirates.

Aug. 3, 2004: Pakistani government officials announce the arrest of several key al-Qaeda suspects.

July 12, 2004: Khaled bin Ouda bin Mohammed al-Harby, a sheik and a confidant of bin Laden, surrenders to Saudi officials in Iran.

July 7, 2004: Six Yemenis are charged with planning the October 2000 bombing of the USS Cole.

June 25, 2004: The group Tawhid and Jihad, led by al-Qaeda-linked militant Abu Musab al-Zarqawi, claims responsibility for a series of attacks across Iraq.

June 18, 2004: Islamic militants with ties to al-Qaeda behead an American hostage, Paul Johnson. Abdulaziz al-Muqrin, the suspected leader of al-Qaeda in Saudi Arabia, is killed in a firefight with Saudi security forces.

May 12, 2004: A video posted on a website linked to al-Qaeda shows the beheading of American hostage Nick Berg. The video is entitled Abu Musab al-Zarqawi Shown Slaughtering an American. Al-Zarqawi is a lieutenant of bin Laden.

April 22, 2004: Saudi authorities blame suicide attacks in downtown Riyadh on al-Qaeda. The attacks killed 10 people.

March 25, 2004: An audio tape believed to be from Ayman al-Zawahri, number two in al-Qaeda, is broadcast on al-Jazeera, calling for the overthrow of the government in Pakistan.

March 11, 2004: Bombs on commuter trains in Madrid kill 190 people and injure more than 1,800. Spain later arrests more than a dozen suspects, many of them from Morocco and believed to have ties to al-Qaeda.

Nov. 11, 2003: Saudis blame al-Qaeda for a suicide car bombing that killed 17 people in Riyadh.

May 1, 2003: U.S. President George W. Bush declares "major combat" over in Iraq.

March 20, 2003: The United States attacks Iraq.

March 1, 2003: Pakistani and U.S. agents arrest Khalid Shaikh Mohammed, one of the suspected masterminds of the Sept. 11 attacks.

Jan. 30, 2003: Shoe bomber Richard Reid is sentenced to life in prison.

Oct. 26, 2003: Russian special forces use gas to retake the theatre. The total death toll, from the gas and from those killed by the hostages is 128. All 41 hostage-takers are also killed.

Oct. 23, 2003: Chechen rebels, believed to be loosely affiliated with al-Qaeda, storm a theatre in Moscow and take audience, actors and crew as hostages.

Oct. 12, 2003: Bombs in two nightclubs in Bali kill 202 people. Authorities later charges members of a local group, Jemaah Islamiyah, which has ties with al-Qaeda.

November, 2002: Osama bin Laden threatens Britain, France, Italy, Canada, Germany and Australia for their support for the United States, saying: "It is time we get even. You will be killed just as you kill, and will be bombed just as you bomb."

March 18, 2002: The United States ends its sweep through the mountains of Afghanistan, Operation Anaconda, but most of the Taliban and al-Qaeda escape.

Dec. 22, 2001: Shoe bomber Richard Reid tries to blow up an American Airlines jet over the Atlantic.

Dec. 11, 2001: The United States files criminal charges against the alleged "20th hijacker" Zacarias Moussaoui.

Dec. 7, 2001: Taliban forces in Kandahar surrender to American troops.

Nov. 13, 2001: Northern Alliance soldiers enter Kabul.

Nov. 9, 2001: The Taliban flee the northern city of Mazar-e-Sharif.

Oct. 9, 2001: Al-Qaeda spokesman Sulaiman Abu Ghaith issues a statement calling for a holy war against the United States.

Oct. 7, 2001: The United States launches air strikes in Afghanistan aimed at al-Qaeda training camps and Taliban bases. Osama bin Laden, in a videotaped message, praises God for Sept. 11 attacks and swears America will never "dream of security" until "the infidels' armies leave the land of Muhammad."

Sept. 11, 2001: Attacks on World Trade Center in New York, Washington and Pennsylvania kill close to 3,000 people. Al-Qaeda is blamed within days of the attacks.

August 2001: Osama bin Laden threatens attacks on U.S.

June 19, 2001: Osama bin Laden releases a taped message, which many believe was the orders that triggered the Sept. 11, 2001, attacks on the United States.

May 29, 2001: A U.S. District Court jury finds four of Osama bin Laden's followers guilty of conspiring to kill Americans, including those killed in the U.S. embassy bombings in Africa.

Oct. 12, 2000: Two suicide bombers, suspected to be associated with bin Laden, attack the navy destroyer USS Cole in Aden, Yemen, killing 17 sailors.

Nov. 4, 1998: A U.S. federal grand jury indicts Osama bin Laden in the bombing of U.S. embassies in Africa.

Feb. 22, 1998: Osama bin Laden calls for attacks on American citizens.

Mid-August 1998: Bin Laden reportedly escapes a strike by 70 U.S. Tomahawk missiles on the Zhawar Kili Al-Badr training camp.

Aug. 7, 1998: Bombs explode at the U.S. embassies in Nairobi, Kenya and Dar es Salaam, Tanzania, killing more than 231 people and injuring 5,000. The U.S. retaliates with air strikes against suspected training camps in Sudan and Afghanistan.

Sept. 1996: Taliban takes control of Afghanistan. It will later offer refuge to Osama bin Laden and al-Qaeda supporters.

June 25, 1996: Bin Laden followers bomb U.S. military base near Dhahran, Saudi Arabia, killing 19 American soldiers and wounding hundreds of Americans and Saudi Arabians.

1996: After Osama bin Laden is expelled from Sudan, al-Qaeda moves its operation to Afghanistan. Iran sponsors a re-organization of al-Qaeda with bin Laden as leader.

Nov. 13, 1995: Seven people, including five Americans, are killed when two bombs explode at a U.S.-Saudi military facility in Riyadh, Saudi Arabia. Osama bin Laden is blamed for the attack.

June 26, 1995: Al-Qaeda tries, unsuccessfully, to assassinate Egyptian President Hosni Mubarak in Addis Ababa, Ethiopia

Oct. 8, 1993: Al-Qaeda supporters attack UN troops in Somalia, killing 18 U.S. servicemen

Feb. 26, 1993: A 500-kilogram bomb explodes in a garage under World Trade Center in New York, killing six and injuring 1,042. Bin Laden associate Ramzi Yousef is sentenced to life without parole in February 1998 for orchestrating the bombing.

1993: Osama bin Laden sets up militant training camps in Sudan and begins searching for nuclear material and weapons.

1989: Osama bin Laden founds an international group known as al-Qaeda, which in Arabic means "the base." It is formed primarily of mujahedeen, meaning holy warriors, and others fighting the Soviets in Afghanistan.