Ayman al-Zawahiri succeeded Osama bin Laden as al Qaeda leader after years as its main organiser and strategist, but his lack of charisma and competition from rival militants Islamic State hobbled his ability to inspire sizeable attacks on the West.

Al Qaeda leader Ayman al-Zawahiri was killed in a U.S. strike in Afghanistan over the weekend, President Joe Biden said on Monday, the biggest blow to the militant group since its founder Osama bin Laden was killed in 2011.