Ayman al-Zawahiri and al Qaeda have been blamed for numerous terrorist attacks worldwide, mainly on Western targets, including the attacks of September 11, 2001, on New York and Washington that killed nearly 3,000 people. Read the full profile
Here's a timeline of some of the charges against al-Zawahiri and key points in his life:
* 1970s – al-Zawahiri works to overthrow Egyptian President Anwar Sadat, and establish an Islamic state.
* 1979 – Travels to Afghanistan to offer his services as a doctor to the rebels fighting the Soviet Union.
* 1981 – After Sadat's assassination, al-Zawahiri is imprisoned on conspiracy charges. He is eventually acquitted.
* 1987 – Al-Zawahiri and Osama bin Laden meet for the first time, in Pakistan.
* 1995 – Travels through the U.S. on a secret fund-raising tour.
* August 6, 1998 – A fax from al-Zawahiri's group is sent to an Egyptian newspaper warning that the Islamic Jihad is seeking revenge against America for the arrest of several of its members.
* August 7, 1998 – Suicide bombers attack the U.S. embassies in Kenya and Tanzania.
* 1998 – The Egyptian Islamic Jihad and al Qaeda merge. Joins with bin Laden and announces the World Islamic Front for the Jihad against the Jews and the Crusaders.
* 1999 – Indicted, along with Osama Bin Laden, by a New York court for the 1998 U.S. Embassy bombings in Nairobi and Dar-Es-Salaam.
* 1999 – Receives a death sentence, in absentia, from an Egyptian court, for an alleged plot against U.S. interests in Albania.
* September 11, 2001 – Terrorist attacks on the World Trade Center and the Pentagon.
* December 2001 – U.S. attack on the al-Zawahiri family residence in Afghanistan kills al-Zawahiri's wife and three children.
* January 13, 2006 – A CIA air strike in Damadola, Pakistan, targets al-Zawahiri, but kills at least 17 other people, including 4 top al-Qaeda officials.
* May 2, 2011 – Osama bin Laden is killed in a raid by U.S. forces in Abbottabad, Pakistan.
* June 8, 2011 – A new video of Zawahiri is released on Islamist websites. The video eulogizes Osama bin Laden and calls him a martyr.