This enabled him to recruit men and raise money to wage a cruel war, mostly against Iraqi civilians. In a macabre innovation, he staged beheadings of Western hostages such as Ken Bigley which were then uploaded to the internet to ensure maximum publicity.

His death in an air strike by American F-16s while in a house north of Baghdad with seven associates, is important in Iraq because he was the most openly sectarian of the Sunni resistance leaders, butchering Shias as heretics as worthy of death as any foreign invader.

His chosen instrument was the suicide bomber usually recruited from outside the country. Their targets were almost invariably young Shia men desperate for work, queuing for jobs as policemen or soldiers. Few of the 20,000 US soldiers killed and wounded in Iraq in the past three years have died at the hands of Zarqawi’s men, according to the US military.

George Bush and Tony Blair welcomed news of the death of the leader of al-Qa’ida in Iraq yesterday. But, paradoxically, among those most pleased by his elimination may be the other insurgent leaders. “He was an embarrassment to the resistance itself,” said Ghassan al-Attiyah, an Iraqi commentator. “They never liked him taking all the limelight and the Americans exaggerated his role.”

Zarqawi owed his rise to the US in two ways. His name was unknown until he was denounced on 5 February 2003 by Colin Powell, who was the US Secretary of State, before the UN Security Council as the link between Saddam Hussein and al-Qa’ida. There turned out to be no evidence for this connection and Zarqawi did not at this time belong to al-Qa’ida. But Mr Powell’s denunciation made him a symbol of resistance to the US across the Muslim world. It also fitted with Washington’s political agenda that attacking Iraq was part of the war on terror.

The invasion gave Zarqawi a further boost. Within months of the overthrow of Saddam Hussein the whole five-million-strong Sunni Arab community in Iraq appeared united in opposition to the occupation. Cheering crowds gathered every time a US soldier was shot or an American vehicle blown up. Armed resistance was popular and for the first time Sunni militants known as the Salafi, religious fundamentalists demonstrating their faith by religious war or jihad, had a bedrock of support in Iraq. Osama bin Laden and his fighters never had this degree of acceptance in Afghanistan and were forced to hire local tribesmen to take part in their propaganda videos.

The next critical moment in Zarqawi’s career was the capture of Saddam Hussein on 15 December 2003. Previously US military and civilian spokesmen had blamed everything on the former Iraqi leader.

No sooner was Saddam captured than the US spokesmen began to mention Zarqawi’s name in every sentence. “If the weather is bad they will blame it on Zarqawi,” an Iraqi journalist once said to me. It emerged earlier this year that the US emphasis on Zarqawi as the prime leader of the Iraqi resistance was part of a carefully calculated propaganda programme. A dubious letter from Zarqawi was conveniently discovered. One internal briefing document quoted by The Washington Post records Brigadier General Kimmitt, the chief US military spokesman at the time, as saying: “The Zarqawi psy-op programme is the most successful information campaign to date.” The US campaign was largely geared towards the American public and above all the American voter. It was geared to proving that the invasion of Iraq was a reasonable response to the 9/11 attacks. This meant it was necessary to show al-Qa’ida was strong in Iraq and play down the fact that this had only happened after the invasion.

In an increasingly anti-American Arab world hostility from the US made it easy for Zarqawi develop his own organisation and finance it. The siege of Fallujah in April 2004 and the storming of the city by US Marines in November the same year saw al-Tawhid wal-Jihad (Monotheism and Jihad), whose name was later changed to al-Qa’ida’s Organisation in Iraq, become a powerful force. The suicide bombing campaign had already begun in November 2003 and was from the beginning directed against Shias as much as foreign troops or officials.

Zarqawi’s war was devised to have the maximum political impact. There was the beheading of foreign captives shown on videos and broadcast via the internet. He was an enemy to America’s liking. Though US military officials in Baghdad openly admitted that few insurgents were non-Iraqi, Zarqawi’s Jordanian origins were useful in suggesting that the insurrection was orchestrated from outside Iraq.

There were always going to be sectarian and ethnic differences between Shia, Sunni and Kurd after the overthrow of Saddam. This would have given a constituency to Zarqawi whatever happened but he also did much to deepen sectarian hatred by killing Iraqi Shia whenever he could. This destabilised the Iraqi government and it also meant that his anti-Shia fanaticism was increasing acceptable in the Sunni community as the Shia retaliated in 2005.

His death may lessen Shia-Sunni sectarianism but it probably comes too late. Diyala, the province where he was killed, is already seeing a savage civil war in which Iraq’s communities hunt each other down and whoever is in the minority is forced to flee, fight or die.

A life of violence

Afghanistan

Zarqawi went to Afghanistan in 1999 to set up his own training camp and forged close links with al-Qa’ida.

UN Bombing

Zarqawi’s group bombed the UN headquarters in Baghdad in August 2003, killing the UN’s top envoy to Iraq.

Beheadings

Zarqawi is believed to have beheaded two US hostages, Nick Berg and Eugene Armstrong, in 2004 and been involved in the killing of Kenneth Bigley.

Amman Bombing

Suicide bombers from Zarqawi’s group staged a triple attack in Jordan in November last year, killing 60.

Suicide Bombings

Zarqawi’s group claimed a number of attacks in Iraq. A bomb in Hilla last year killed 125, the single deadliest incident.

Sectarian Violence

Last week Zarqawi released an audiotape urging fellow Sunnis to kill Shias.