Five years after the killing of Al-Qaeda chief Osama bin Laden, the network he founded is far from dead even if it has suffered a series of setbacks. Replaced as the pre-eminent global jihadist power by the Islamic State group, Al-Qaeda nonetheless remains a potent force and dangerous threat, experts say.
With last year's Charlie Hebdo massacre in Paris and a wave of shootings in West Africa, Al-Qaeda has shown it can still carry out its trademark spectacular attacks.
And in Syria and Yemen its militants have seized on chaos to take control of significant territory, even presenting themselves as an alternative to the brutality of IS rule.
By the time US special forces killed bin Laden in Pakistan on May 2, 2011, the group he founded in the late 1980s had been badly damaged, with many of its militants and leaders killed or captured in the US "War on Terror".
Dissention grew in the jihadist ranks as new Qaeda chief Ayman al-Zawahiri struggled in bin Laden's place, until one of its branches, originally Al-Qaeda in Iraq, broke away to form the Islamic State of Iraq and the Levant (ISIL).
After seizing large parts of Iraq and Syria in 2014, the group declared a "caliphate" in areas under its control, calling itself simply the Islamic State. IS has since eclipsed its former partner, drawing thousands of jihadists to its cause and claiming responsibility for attacks that have left hundreds dead in Brussels, Paris, Tunisia, Turkey, Lebanon, Yemen, Saudi Arabia and on a Russian airliner over Egypt.
Its self-declared "emir" Abu Bakr al-Baghdadi has won pledges of allegiance from extremist groups across the Middle East and beyond, with especially powerful IS affiliates operating in Egypt's Sinai Peninsula and in Libya.
Jean-Pierre Filiu, a Paris-based expert on Islam and jihadist groups, said IS has been especially effective at using new technology to surpass its less tech-savvy rival.