On April 20, Iraqi militia fighters paraded a body in a glass coffin through the streets of Baghdad. The body was purportedly that of Ezzat al-Douri, who was right-hand man to the late Iraqi President Saddam Hussein and the most wanted member of the ousted Baathist regime to remain at large since the U.S. invasion of Iraq in 2003.

The Shi’ite militia fighters claim that Douri and several bodyguards were killed in an ambush near the city of Tikrit, but the Iraqi government still has not confirmed through DNA testing that the body is that of Douri. And while Douri has been erroneously reported as killed or captured by Iraqi officials in the past, this is the first time a body with features similar to Douri’s has been paraded in public.

Douri was at the nexus of a marriage of convenience between former officers of Hussein’s Baath Party and Sunni militants like those of Islamic State. While Islamic State fighters took the most prominent role in the sweep through northern and central Iraq last year, they were able to capture large swaths of territory from the Iraqi government thanks to an alliance with a network of former Hussein regime loyalists who had deep ties to Sunni tribes in cities like Mosul and Tikrit.

The former Baathists, who include former intelligence officers and elite Republican Guard troops, coalesced in 2007 as a group called the Army of the Men of the Naqshbandi Order. With Douri as its reputed leader, the group emerged soon after the Shi’ite-led government in Baghdad executed Hussein. The Naqshbandi Order sought to counter Iranian influence, tap into the disillusionment of Iraq’s Sunni minority and try to restore Sunni rule over the country.

Shortly after Islamic State militants captured Mosul last June, with help from the Naqshbandi Order and its tribal allies, Douri issued an audio message praising the Sunni militants and urging Iraqis to join the fight. “Join the ranks of the rebels who liberated half the country,” Douri said. “The liberation of Baghdad is around the corner. Everyone should contribute to complete the liberation of the beloved country because there is no honor or dignity without it.”

The Washington Post reported last month that former Iraqi Baathists are playing a leading role in Islamic State, especially as members of its shadowy military and security committees. Because the Baathists have deep social, financial and cultural ties to many areas that are now under Islamic State’s control, it will be difficult for the Iraqi government to dislodge the militants from those areas. And even when Baghdad is able to recapture territory, the militants and their Baathist allies undermine the central government’s efforts to restore order.

But the Baathist alliance with Sunni militants predates the rise of Islamic State. After U.S. forces ousted Hussein’s regime in 2003, Douri went into hiding and began to mastermind the Sunni-led insurgency, first against the U.S. occupation and then the Shi’ite-led Iraqi government.

Douri was the king of clubs in decks of cards given to American forces in 2003 to identify the most wanted Baathist regime leaders. He was initially No. 6 on the most wanted list of 55 Iraqis, but after Hussein and other regime figures were killed or captured, Douri became the most wanted fugitive. U.S. officials placed a bounty of $10 million on his head.

In the fall of 2003, American officials said Douri was involved in recruiting foreign jihadists and funding attacks on U.S. troops. That assessment was based on accounts from captured members of Ansar al-Islam, an al Qaeda-linked group that U.S. officials blamed for a series of suicide bombings and other attacks on American forces and Iraqi civilians. Although he was in poor health, some U.S. officials said Douri fled to neighboring Syria, where he reportedly worked with Syrian intelligence operatives to reestablish elements of the Baath Party within Iraq.

Both the Baathists and the Islamic militants were able to cultivate support from ordinary Sunnis who were alienated by the sectarian policies of former Iraqi Prime Minister Nouri al-Maliki. The new premier, Haider al-Abadi, must assure Iraq’s Sunnis that he will be able to reverse the legacy of his divisive predecessor. Since Abadi took office last September, Sunni political leaders have made several demands on him: amnesty for tens of thousands of Sunnis imprisoned, in many cases without judicial review, by Maliki’s regime in the name of fighting terrorism; greater power in the new government; an end to aerial bombardment of Sunni towns, and a more significant role in the Iraqi security forces, which Maliki cleansed of many senior Sunni officers.

Today, Shi’ite militias are taking the lead in the fight against the Sunni jihadists and in the process further alienating the Sunni community by committing new atrocities. Many Sunnis cringe at the memories evoked by the reestablishment of Shi’ite militias, which carried out widespread kidnappings, torture and killings of Sunnis during the sectarian war that raged in Iraq from 2005 through 2008.

Douri was born to a peasant family in Al Dour, a village close to Hussein’s hometown of Tikrit in northern Iraq. He was one of three original plotters who carried out the 1968 coup that brought the Baath Party to power in Iraq to survive Hussein’s repeated purges of the party.

Under Hussein’s rule, Douri served as vice chairman of the Revolutionary Command Council, the second most powerful post in Iraq. (His daughter also was briefly married to Hussein’s son, Uday.) Douri played a central role in the wars against Iran and Kuwait, and the brutal repression of Kurds and Shi’ites during a 1991 uprising. He is also believed to have overseen Iraq’s chemical weapons when they were used against Kurdish rebels in 1988.

Because Hussein rarely traveled outside Iraq, Douri often represented the Baathist regime at international meetings. At an Islamic summit two weeks before the U.S. invasion in March 2003, Douri derided a Kuwaiti official who had insulted the Iraqi president, shouting, “Shut up, you monkey! Curse be upon your mustache, you traitor.”

Such antics made Douri a folk hero, and his stature among Sunnis grew significantly after he was able to elude capture for 12 years. His death is a blow to the alliance of Baathists and Islamic militants, but with Sunni grievances still unresolved, that bond will endure.