From humble origins in the Jordanian city of Zarqa, Abu Musab al-Zarqawi started off as a petty criminal. Radicalised in jail, he went on to fight the Soviets in Afghanistan.
His notoriety grew after his return from Afghanistan. After another spell in prison, he was accused of plotting attacks on tourist sites in Jordan.
Zarqawi is said to have travelled back to Afghanistan to fight with the Taleban. Reportedly injured in a US strike, he re-surfaced in Iraq as head of the Tawhid and Jihad group.
His group gained a reputation for bomb attacks on Shias and for the release of videos, one apparently showing Zarqawi personally beheading a foreign hostage.
US forces said Zarqawi was their biggest foe in Iraq and placed a huge bounty on his head. Pictures were released, apparently showing him in different guises.
In 2004, Zarqawi formally aligned Tawhid and Jihad with Osama Bin Laden's al-Qaeda. More images were released to help in the hunt for him.
US forces swooped on vast swathes of western Iraq to try to cripple Zarqawi's network. Reports pinpointed him at different times in Falluja, Ramadi and Tal Afar.
In early 2006, Zarqawi appeared unmasked in a video which showed him apparently planning attacks.
He was also seen firing a machine gun in the desert in images clearly designed to show he was still at large - and in command of the insurgency.
These images may be the last ones of him alive. The Iraqi prime minister has said he was killed in an air strike.