@revel,
He may not have called himself al-Qaida until 2004, but his association and links to Bin Laden go back to 1999 and he was actively involved with al-Qaida before the March 20, 2003 invasion of Iraq.
A timeline of events in Abu Musab al-Zarqawi's life as leader of al-Qaida in Iraq:
Oct. 20, 1966: Born Ahmad Fadhil Nazzal al-Khalayleh in Jordan, part of Bani Hassan Bedouin tribe.
1980s: Embraces Islamic militancy, makes first trips to Afghanistan to fight Soviet invasion.
Mid-1990s: Returns to Jordan, is arrested, solidifies radical ideology in prison. Shares cell block with militant cleric Isam Mohammed al-Barqawi, known as Abu Muhammed al-Maqdisi. Adopts extremist strain of Islam that brands enemies as "infidels" worthy of death.
1999: Returns to Afghanistan after prison release. Forms links with al-Qaida chief Osama bin Laden.
Late 2001: Flees Afghanistan during U.S.-led ouster of Taliban. Passes through Iran to Iraq.
Oct. 2002: U.S. diplomat Laurence Foley slain in Jordan, believed to be first terror operation by al-Zarqawi followers.
Feb. 2003: Secretary of State Colin Powell, in presentation to U.N. Security Council, cites al-Zarqawi presence in Iraq as proof of link between Saddam Hussein and al-Qaida. U.S. counterterrorism officials later cast doubt on connection.
(Although Zarqawi had still not declared bayat to bin Laden, he met with al-Qaeda's military chief, Muhammad 'Ibrahim Makawi, aka Saif al-Adel, in March 2003. Zarqawi agreed to coordinate the entry of al-Qaeda operatives into Iraq from Syria. This essentially made Zarqawi the terrorist 'Emir' of Iraq.15)
March 20 - Invasion of Iraq
Aug. 2003: Al-Zarqawi group, called "Monotheism and Jihad," stages suicide attacks on U.N. headquarters in Baghdad and Shiite shrine in Najaf, seen by many as start of Iraqi insurgency.
April 2004: Beheads U.S. hostage Nicholas Berg, posts videotape of killing on Internet.
May 18, 2004: Car bomb by al-Zarqawi followers assassinates president of now-disbanded Iraqi Governing Council.
July 2004: United States sets $25 million bounty for al-Zarqawi.
Sept. 2004: Beheads U.S. hostage Eugene Armstrong, posts videotape of killing on Internet.
Oct. 2004: Vows fealty to bin Laden, changes name of group to "al-Qaida in Iraq."
Feb. 2005: Suicide bombing against Iraqi security recruits in Hillah kills 125. Claimed by al-Qaida in Iraq, is single deadliest attack of insurgency.
Nov. 9, 2005: Triple suicide bombing against hotels in Amman, Jordan, kills 60, mostly Sunni Muslims. Attack draws criticism from fellow Islamic militants.
Jan. 5, 2006: Al-Zarqawi fighters blamed for string of suicide bombings against Shiites in holy city of Karbala and police station north of Baghdad, killing at least 130. Attacks came weeks after parliament election.
Jan. 2006: Announcement that Al-Zarqawi movement joining umbrella organization of Iraqi insurgents called the Shura Council of Mujahedeen. Seen as attempt to give Iraqi face to al-Qaidi in Iraq, believed to be mainly non-Iraqi, Arab fighters.
June 7: Al-Zarqawi and several aides killed in targeted U.S. air strike. Followers vow to continue holy war.
Source:
http://www.pwhce.org/zarqawi.html
http://www.washingtonpost.com/wp-dyn/content/article/2006/06/08/AR2006060800299.html