ISLAMABAD – Egyptian-born doctor and surgeon Ayman al-Zawahri is al Qaeda's second-in-command expected to succeed Osama bin Laden following his killing in a firefight with U.S. forces in Pakistan.
Zawahri has been the brains behind bin Laden and his al Qaeda network, and at times its most public face, repeatedly denouncing the United States and its allies in video messages.
In the latest monitored by the SITE Intelligence Group last month, he urged Muslims to fight NATO and American forces in Libya.
"I want to direct the attention of 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 neighbors 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," Zawahri said.
Born into an upper-class family of scholars and doctors in an upscale Cairo neighborhood, the cerebral Egyptian in his late-50s is second after bin Laden on the FBI "most wanted terrorists" list.
Both bin laden and Zawahiri eluded capture when U.S.-led forces toppled Afghanistan's Taliban government in late 2001 after al Qaeda's September 11 attacks on U.S. cities.
But on Sunday bin Laden was killed in a firefight with U.S. forces and his body was recovered, U.S. President Barack Obama said. There was no word on Zawahri.
Bespectacled, with grey hair and a grey beard, Zawahri won prominence in November 2008, when he attacked then U.S. President-elect Obama as a "house Negro," a racially-charged term used by 1960s black American Muslim leader Malcolm X to describe black slaves loyal to white masters.
In a subsequent video, in September 2009, Zawahri returned to the attack on Obama, saying he was no different from his predecessor George W. Bush.
"America has come with a new deceptive face ... It plants the same dagger as Bush and his predecessors did. Obama has resorted to the policies of his predecessors in lying and selling illusions," said Zawahri, clad in white robe and turban.
Like bin Laden, Zawahri has long been thought to be hiding along the rugged Afghan-Pakistan border. The last video of Zawahri and bin Laden together was broadcast by al Jazeera on September 10, 2003. It showed them walking in mountains, calling for jihad and praising the September 11 hijackers.
Analysts have described Zawahri as al Qaeda's chief organizer and bin Laden's closest mentor. "Ayman is for bin Laden like the brain to the body," said Montasser al-Zayat, a lawyer in Cairo who once represented Zawahri.
In a video after the September 11 attacks, Zawahri called them a "great victory" achieved "thanks to God".
He has not always been so ebullient.
As U.S.-led forces drove out the Taliban in 2001, Afghan sources described him flying into a fury at the nonchalance of Taliban fighters playing badminton behind the front lines while U.S. bombs rained from the skies.
Zawahri and bin Laden met in the mid-1980s when both were in the Pakistani city of Peshawar to support guerrillas fighting the Soviets in Afghanistan, and worked closely thereafter. But the alliance was not Zawahri's first foray into militancy.
Born in 1951, he was the son of a pharmacology professor and grandson of the grand imam of Al Azhar, one of the most important mosques in the Muslim world.