Born in 1957, into a wealthy family, at school and university he joined the Muslim Brotherhood.
When the Soviets invaded Afghanistan in 1979, he collected money and supplies for the Afghan resistance, the mujahideen.
He made further trips, and joined the fighting. As a wealthy Saudi, he stood out and acquired a following, and other Arabs joined the Afghan Muslims. He organised a guesthouse and camps, naming them al-Qaeda.
The Afghan jihad against the Soviet army was backed with American dollars, and supported by the governments of Saudi Arabia and Pakistan. But after the Soviet withdrawal, bin Laden became disillusioned by the lack of recognition for his achievements. Half a million US soldiers were invited onto Saudi soil, a historic betrayal in bin Laden's eyes.
Bin Laden began to direct his efforts against the US and its allies in the Middle East. In 1991 he was expelled because of his anti-government activities. His bank accounts were frozen and his movements limited. As he felt himself under increasing pressure bin Laden became more radical.
By the mid-1990s, he was calling for a global war against all Americans and Jews and, in 1998, he issued his famous fatwa (religious ruling), amounting to a declaration of war against the US.
Experts say bin Laden is part of an international Islamic front, bringing together Saudi, Egyptian and other groups.
He has been accused of masterminding the bombing of US embassies, the World Trade Centre destruction, and other attacks. He was thought to be in Afghanistan after 11th September 2001.
Al-Qaeda,or groups linked to it, have continued to carry out attacks, even after it lost its bases in Afghanistan with the removal of the Taleban in 2001.
Bin Laden was tracked down to a compound in Abbottabad, Pakistan and on 2 May 2011 he was killed by US Navy SEALs. His body was buried at sea within 24 hours of his death.