The U.S. State Department is offering a reward of up to $25 million
for information leading directly to the capture of al-Zawahiri.
1981 - Al-Zawahiri is among hundreds of suspects arrested after the assassination of Egyptian President Anwar Sadat.
He is not charged in connection with the assassination but is sentenced to three years in prison for weapons possession.
August 7, 1998 -
Suicide bombers attack the U.S. embassies in Kenya and Tanzania
1998 - The Egyptian Islamic Jihad, led by al-Zawahiri, and al Qaeda merge.
Al-Zawahiri and bin Laden issue a fatwa, published in an Arab newspaper, stating that Muslims should kill Americans around the world.
October 2012 - In a video posted on jihadist websites, al-Zawahiri praises the kidnapping of Warren Weinstein,
an American citizen in Pakistan
. Weinstein, a development expert, was abducted in 2011 from his home in Lahore, Pakistan. Al-Zawahiri encourages followers to kidnap more westerners.
April 2014 -
Audio of a two-part interview purportedly with al-Zawahiri is posted on a radical Islamist website.