Years before Darfur's most powerful and charismatic rebel leader became enemy No. 1 of Sudan's Arab-dominated government, Khalil Ibrahim was a member of the movement that brought it to power in a coup.
Ibrahim was part of the National Islamic Front, which seized power in a bloodless military putsch in 1989. Like many of the movement's members, Ibrahim, a physician, returned to Sudan from Saudi Arabia after the coup and was soon after appointed state minister for Darfur, the vast western desert region of the country.
Years later, having grown frustrated with the continued marginalisation of ethnic African Darfurians, Ibrahim joined a group of dissidents — most of them from the Darfur region — who published the "Black Book," a scathing exposure of the Arab domination of politics and resources in Sudan.
Full-blown war broke out in 2003.
On Sunday, Sudan's army said, it killed Ibrahim, its fiercest enemy, in a military offensive in the North Kordofan region, which borders Darfur. He was in his 50s.
Ibrahim first made his split with the government of army general Omar Al-Bashir public when he sided with another key figure who had turned against Sudan's president.
Hassan Al-Turabi, the president's one-time mentor and movement ideologue, fell out with Al-Bashir and was pushed from government. For years afterward, the government accused Al-Turabi of supporting Ibrahim's group, and it has kept the elderly politician in and out of prison for years.
Ibrahim announced the formation of Darfur's Justice and Equality Movement, or JEM, from exile in early 2000. Along with an array of other rebel groups, he launched the struggle against Khartoum's marginalisation of Darfur from the remote western region.
After years of conflict, Ibrahim's group emerged as the most formidable military challenge to Khartoum's government.
In its most stunning display of might, the rebels of JEM in 2008 blazed across the desert in trucks loaded with men and guns right up to the capital's outskirts and launched an attack that shook the government. At least 200 people, including rebels, civilians and security, died in that attack.
The short-lived assault was the first of its kind by the Darfur rebels. The government soon afterward went into peace talks that produced deals with many rebel factions.
Ibrahim's group was among them at first, but it soon dropped out over disagreement on the release of prisoners and representation in a future government. He later extended his group's operation in provinces neighboring Darfur and threatened to take the fight to Khartoum.
Ibrahim's rebel movement is made up of fighters largely from his own Zaghawa tribe, which is based in Darfur and to the west, across the border in Chad and known for its formidable fighting ability.
Ibrahim tried to dominate other rebel groups in an attempt to form a unified position. But divisions along tribal lines and Ibrahim's own Islamist politics kept him from drawing a slew of rebel groups together under his leadership.
He lashed out at some of these groups, accusing them of having been infiltrated by the government and describing them dismissively as "individuals with mobile phones who appear on satellite stations."
Ibrahim was, however, one of the most successful rebel leaders in securing support from Sudan's neighbors Libya and Chad in his fight against Al-Bashir's regime — at least for a time.
His fortunes began to turn when the president of Chad reached a pact with Al-Bashir to end his support for JEM and other rebel groups. Ibrahim was expelled from Chad and sought refuge in Moammar Gadhafi's Libya until Gadhafi's ouster and killing this year in that country's civil war.
Since then, Ibrahim's exact location had not been known.
Sudan's government said it attacked his convoy as he made his way to Sudan's newly born neighbor, South Sudan, which seceded from Khartoum in June as a result of a separate, decades-long war against the Arab-dominated government of Sudan.
The Darfur conflict and the related humanitarian crisis killed an estimated 300,000 people and displaced 2.7 million, according to UN figures. The fighting has tapered off since 2009, but the conflict continues to simmer and local grievances over government neglect remain.
Just days ago, JEM had renewed its threats against Khartoum, saying it would take the fight from the remote western region to the capital to topple Al-Bashir's regime.
Partially encouraged by the wave of Arab Spring uprisings, some in Sudan have looked to Darfur's rebels as the most organised opposition to the regime and a force that could potentially challenge its decades-long hold on power.
Ibrahim's killing, however, throws the future of his rebel movement in doubt.