Feb. 18, 2011 - Zawahiri condemns Egypt's regime under toppled leader Hosni Mubarak as corrupt, and praises an Islamic state as an appropriate alternative, in an audio recording posted on the Internet.

April 15 - Zawahiri says Muslims should fight NATO in Libya in an audio message. "I want to say to our Muslim brothers in Libya, Tunisia, Algeria, and the rest of the Muslim countries, that if the Americans and the NATO forces enter Libya, then their neighbours in Egypt and Tunisia and Algeria and the rest of the Muslim countries should rise up and fight both the mercenaries of Gaddafi and the rest of NATO."

May 2 - Osama Bin Laden is killed in Pakistan by U.S. forces after a 10-year hunt.

June 8 - Zawahiri mourns bin Laden in a 28-minute eulogy on YouTube. He calls on Pakistanis to rise against what he called their corrupt rulers "just as your brothers in Tunisia, Egypt, Libya and Syria have done". Following is a timeline of some of the major statements attributed to Ayman Zawahiri in the past two years, as an Islamist website announced on Thursday he had taken command of Al-Qaeda.

June 2, 2009 - Zawahiri urges Egyptians to reject a visit by U.S. President Barack Obama to Egypt during which he delivered a message to Muslims. He described Obama as a "criminal" and said his messages to Muslims had "already been received (through) ... a bloody campaign against Muslims in Swat" in Pakistan.

July 19, 2010 - In an Internet message, Zawahiri mocks Obama for voicing confidence over victory in Afghanistan. He also says Arab government leaders allied to the West are more harmful to the Palestinians than Israel.

July 27 -  Zawahiri, in an audio recording, condemns a French move to ban Islamic face veils and, in an Internet message, urges Yemeni clerics to call for jihad against U.S. operations in Yemen.

Sept. 15 - Zawahiri releases an audio recording calling on Pakistanis to revolt.

Nov. 4 - In a recording posted on the internet, Zawahiri calls for retaliation against the United States for sentencing a female Pakistani neuroscientist to life in prison for shooting at FBI agents and soldiers.
-- Aafia Siddiqui was arrested in Afghanistan in 2008 by Afghan police, who said she was carrying 900 grams (2 lb) of sodium cyanide and crumpled notes referring to mass-casualty attacks and New York landmarks.