With that offer in 1980, al-Zawahri began a life that for more than three decades took him to the top of the world’s most feared terrorist group, al-Qaeda, after the death of Osama bin Laden. Already a seasoned campaigner who had sought to overthrow Egypt’s “infidel” regime since the age of 15, al-Zawahri took a trip to Afghanistan’s war zone that lasted just a few weeks but opened his eyes to new possibilities. What he saw was “the training course preparing the Muslim mujahideen youth to begin their coming battle with the great power that would rule the world: America,” he wrote in a 2001 autobiography-manifesto. Al-Zawahri, 71, was killed over the weekend by a US drone strike in Afghanistan. President Joe Biden announced the death Monday night in an address to the nation. The strike is likely to lead to more turmoil within the organization than bin Laden’s death in 2011, since it is much less clear who will succeed him. Al-Zawahri became instrumental in directing the jihadist movement to target the United States as the right-hand man of bin Laden, the young Saudi millionaire he met in the Afghanistan-Pakistan region. Under their leadership, the Al Qaeda terrorist network carried out the deadliest attack ever on American soil, the suicide bombers of September 11, 2001. The attacks on the World Trade Center and the Pentagon made bin Laden America’s enemy No. 1. But he probably never could have done it without his deputy. While bin Laden came from a privileged background in a prominent Saudi family, al-Zawahri had the experience of an underground rebel. Bin Laden provided al-Qaeda with charisma and money, but al-Zawahri brought the tactical and organizational skills needed to forge fighters into a network of cores in countries around the world. “Bin Laden always looked up to him,” said terrorism expert Bruce Hoffman of Georgetown University. Al-Zawahri “spent time in an Egyptian prison, was tortured. He was a jihadist from the time he was a teenager.” When the 2001 US invasion of Afghanistan destroyed al-Qaeda’s safe haven and dispersed, killed and captured its members, al-Zawahri ensured al-Qaeda’s survival. He rebuilt his leadership in the Afghanistan-Pakistan border region and installed allies as lieutenants in key positions. He also became the public face of the movement, sending a steady stream of video messages while bin Laden was largely in hiding. With his bushy beard, heavy-rimmed glasses and an obvious bruise on his forehead from bowing in prayer, he was notoriously prickly and meticulous. He picked ideological battles with critics within the jihadist camp, wagging his finger imperiously in his videos. Even some key figures in al-Qaeda’s central leadership were put off, calling him too controlling, secretive and divisive – unlike bin Laden, whose mild-mannered presence many fighters described in cultish, almost spiritual terms. However, he transformed the organization from a centralized planner of terrorist attacks to the head of a franchise chain. He led the creation of a network of autonomous branches throughout the region, including Iraq, Saudi Arabia, Yemen, North Africa, Somalia and Asia. In the decade after 9/11, al-Qaeda inspired or had a direct hand in attacks in all these regions, as well as in Europe, Pakistan and Turkey, including the 2004 train bombings in Madrid and the London bombings in 2005. More recently, al Qaeda’s Yemeni affiliate proved capable of planning attacks on American soil with an attempted bombing in 2009 of a U.S. airliner and an attempted bombing the following year. After bin Laden was killed in a US raid on his compound in Abbottabad, Pakistan, al-Qaeda named al-Zawahri as its top leader less than two months later. Jihad against America “doesn’t stop with the death of a commander or leader,” he said. Hunt America, who killed the leader of the mujahideen and threw his body into the sea. The 2011 Arab Spring uprisings around the Middle East dealt a major blow to al-Qaeda, showing that jihad was not the only way to get rid of Arab autocrats. It was mainly liberals and pro-democracy leftists who led the uprising that toppled Egyptian President Hosni Mubarak, the long-term goal that al-Zawahri failed to achieve. But al-Zawahri sought to ride the wave of uprisings, insisting they would have been impossible if the 9/11 attacks had not weakened America. And he urged Islamic hardliners to take power in nations where leaders had fallen. Al-Zawahri was born on June 19, 1951, the son of an upper-middle-class family of doctors and scholars in the Maadi suburb of Cairo. His father was a professor of pharmacology at Cairo University’s medical school, and his grandfather, Rabia al-Zawahri, was the grand imam of Al-Azhar University, a leading center of religious studies. From a young age, al-Zawahri was rekindled by the radical writings of Sayed Qutb, the Egyptian Islamist who taught that Arab regimes were “infidels” and should be replaced by Islamic rule. In the 1970s, as he earned his medical degree as a surgeon, he became active in fighting circles. He merged his own militant cell with others to form the Islamic Jihad group and began trying to infiltrate the military – at one point even storing weapons in his private clinic. Then came the assassination of Egyptian President Anwar Sadat in 1981 by Islamic Jihad fighters. The assassination was carried out by a different cell of the group – and al-Zawahri wrote that he learned of the plan just hours before the assassination. But he was arrested along with hundreds of other activists and served three years in prison. During his imprisonment, he was reportedly severely tortured, a factor that some say made him a more violent radical. After his release in 1984, al-Zawahri returned to Afghanistan and joined Arab fighters from across the Middle East fighting alongside the Afghans against the Soviets. It hosted bin Laden, who became a heroic figure for his financial support of the mujahideen. Al-Zawahri followed bin Laden to his new base in Sudan, and from there he led a reconstituted Islamic Jihad group in a brutal bombing campaign aimed at toppling the allied government of Egypt. In the most daring attack, Jihad and other militants attempted to assassinate Egyptian President Hosni Mubarak during a 1995 visit to Ethiopia. Mubarak escaped a hail of gunfire aimed at his motorcade, and his security forces crushed the militant movement in Egypt in the ensuing crackdown. The Egyptian movement failed. But al-Zawahri would bring to al-Qaeda the tactics he learned in Islamic Jihad. He promoted the use of suicide bombings to become Al Qaeda’s trademark. He planned a suicide bombing of the Egyptian embassy in Islamabad in 1995 that killed 16 people — foreshadowing the more devastating 1998 al Qaeda bombings of US embassies in Kenya and Tanzania that killed more than 200, for which he was blamed al-Zawahri in the United States states. In 1996, Sudan expelled bin Laden, who took his fighters back to Afghanistan, where they found a safe haven under the radical Taliban regime. Once again, al-Zawahri followed. Two years later, their bond was sealed when bin Laden, al-Zawahri and other militant leaders issued the “Declaration of Jihad against Jews and Crusaders.” He announced that the United States was the foremost enemy of Islam and instructed Muslims that it was their religious duty to “kill the Americans and their allies.” The message sanctified a dramatic change al-Zawahri underwent under bin Laden’s influence, shifting from his long-standing strategy of attacking the “near enemy”—US-allied Arab regimes such as Egypt—to targeting the “distant enemy ”, the United States itself. Some in al-Zawahri’s Islamic Jihad broke away, opposed to the move. And some al-Qaeda fighters whose relationship with bin Laden predates al-Zawahri have always seen him as an arrogant invader. “I have never taken orders from al-Zawahri,” Fazul Abdullah Mohammed, one of the network’s leading figures in East Africa until his death in 2011, quipped in a memoir posted online in 2009. “We do not accept orders from no one but our historical leadership.” The alliance was soon followed by the bombings of US embassies in Africa, followed by the 2000 suicide bombing of the USS Cole off the coast of Yemen, an attack al-Zawahri is believed to have helped orchestrate. When the US invaded Afghanistan, al-Zawahri and bin Laden fled to Pakistan as a US airstrike killed al-Zawahri’s wife and at least two of their six children in the southern Afghan city of Kandahar. The CIA came tantalizingly close to possibly capturing al-Zawahri in 2003 and killing him in 2004. The CIA thought it finally had al-Zawahri in its sights in 2009, only to be outwitted by a double agent who blew himself up, killing seven service employees and wounding six others in Khost, Afghanistan. In his 2001 treatise, “Knights Under the Prophet’s Banner,” al-Zawahri laid out the long-term strategy for the jihadist movement — to inflict “as many casualties as possible” on the Americans while trying to consolidate control over a nation as basis “to begin the battle to restore the holy caliphate” of Islamic rule throughout the Muslim world. Al Qaeda invaded Europe. The bombers in the Madrid attacks that killed 191 are said to have been inspired by al Qaeda, although direct links remain uncertain. Al-Zawahri claimed al-Qaida’s responsibility for the 2005 London bombings that killed 52 people, saying some of the attackers were trained at al-Qaida camps. Not all terror campaigns were successful. Al-Qaeda’s branch in Saudi Arabia was crushed in 2006. Al-Zawahri himself had to write to the head of Al-Qaeda’s branch in Iraq, Abu Musab…