Osama bin Laden was a militant leader, known as the founder and first general emir of al-Qaeda. An ideologically pan-Islamist figure, Bin Laden actively participated in the Afghan mujahideen against the Soviet Union and supported the Bosnian mujahideen during the Yugoslav Wars. He was staunchly opposed to American foreign policy in the Middle East, declaring war on the United States in 1996.

Bin Laden was the mastermind behind the September 11, 2001 attacks in the United States, which resulted in nearly 3,000 casualties, mostly civilians. Born in Riyadh to the aristocratic bin Laden family, he pursued education at various Saudi and foreign universities until 1979. His involvement in the mujahideen began during the Soviet invasion of Afghanistan.

In 1984, Bin Laden co-founded Maktab al-Khidamat, recruiting foreign fighters into the Afghan war. With the end of the Soviet war in Afghanistan, he established al-Qaeda in 1988 to lead a global jihad. During the Gulf War, his offer to support Saudi Arabia against Iraq was rejected, leading to his eventual expulsion from Saudi Arabia in 1991.

After moving first to Sudan and later to Afghanistan, Bin Laden, supported by the Taliban, declared a holy war against the U.S. Following al-Qaeda's bombings of U.S. embassies in East Africa, he was indicted by the U.S. courts and added to the FBI's Most Wanted lists. The United Nations designated al-Qaeda as a terrorist organization in 1999.

The September 11 attacks prompted the U.S. invasion of Afghanistan, initiating the War on Terror. Bin Laden evaded capture for years, hiding in Afghanistan's mountains and later in Pakistan. He was killed by U.S. special operations forces on May 2, 2011, in Abbottabad, Pakistan. His body was buried at sea, and he was succeeded by Ayman al-Zawahiri.