Abu Musab al-Zarqawi
Abu Musab al-Zarqawi (Arabic: أبو مصعب الزرقاوي; b. 1966, d. June 7, 2006) was the Jordanian-born Islamic insurgent head of al-Tawhid wal-Jihad (Group of Monotheism and Jihad,) which later became al-Qaeda in Iraq. A notorious figure associated with Osama bin Laden, he was known for high-profile bombings such as those of the UN office in Bagdad and Shiite Mosques and for bloody assassinations, beheadings of foreign hostages, and mayhem that was intended to drive Iraq into civil war.
Zarqawi rose to prominence as an "Afghan Arab" - leading foreign fighters in the "jihad" against Soviet forces in Afghanistan in the 1980s.  But after the defeat of the Soviets, Zarqawi went back to Jordan with a radical Islamic agenda. He spent seven years in prison in Jordan for conspiring to overthrow the monarchy and establish an Islamic caliphate. He fled Jordan after release.
After being chased out of Afghanistan by the U.S. in 2003, Zarqawi relocated his al Qaeda affiliate Group of Monotheism and Jihad to Iraq. By 2004, Zarqawi had already claimed 25 attacks against US and its allied Iraqi forces. His attacks eventually occurred daily until he was killed by a precision U.S. airstike in 2006.