One year ago today, a voice recording was published online in which the jihadi leader Abu Bakr al-Baghdadi announced the creation of the Islamic State of Iraq and the Levant, or ISIL.

Baghdadi explained that the ISIL was the next step in the evolution of his jihadi proto-state, called the Islamic State in Iraq, which would now formally expand into Syria. Until recently, the Iraqi “state” was widely seen as a formal al-Qaeda branch, having evolved in 2006 out of al-Qaeda in Mesopotamia—a group created to fight U.S. forces in 2004—although that view is now being questioned.

After the outbreak of revolution in Syria, Baghdadi had used his base in Iraq to help establish the Nusra Front, a jihadi faction working inside Syria. He now claimed full ownership of the Syrian jihad, merging the two Syrian and Iraqi movements into one single “state” under his own leadership and under the ISIL name.

The Syrians Refuse to Comply

Things didn’t play out exactly as he had hoped, of course. Many other Islamists protested, and the following day, the Nusra Front’s top commander, a Syrian known as Abu Mohammad al-Golani, pushed back against Baghdadi’s description of him as “one of our soldiers.”

Golani insisted that even though the Nusra Front had received help from the ISIL and was thankful for that, it was a Syrian jihadi group rather than a cross-border movement and that he would lead it alone. Sensing his precarious position, given that many of his fighters and commanders were in fact loyal to Baghdadi—who had sent them to Syria in the first place—Golani took the opportunity to “reaffirm” his loyalty to international al-Qaeda leader Ayman al-Zawahiri, asking him to arbitrate the dispute.

Zawahiri’s Failed Mediation

When Zawahiri came down on Golani’s side in an internal message dispatched in May 2013, he was simply ignored by Baghdadi. Someone quickly leaked Zawahiri’s letter to Al Jazeera—perhaps it was Golani’s side, or intelligence services eager to see the dispute continue in public. But Zawahiri was again brusquely brushed aside by Baghdadi, and worse criticism followed from the ISIL’s official spokesperson, a Syrian from Binnish known as Abu Mohammed al-Adnani.

In doing so, the ISIL had begun to publicly affirm its own independence after many years of purposefully undefined ties to al-Qaeda. An uneasy coexistence settled in among the Syrian jihadis, with the Nusra Front and the ISIL cooperating splendidly in some areas of Syria and keeping a wary distance in others.

The War Against the ISIL

During the summer and autumn, the ISIL’s consolidation as a separate entity in both Syria and Iraq, and its aggressive attempts to dominate and absorb smaller rebel factions, began to spark conflict across northern Syria.

In January 2014 these tensions erupted into open war between the ISIL, on one side, and a coalition of northern groups that included strict Salafis like Ahrar al-Sham of the Islamic Front coalition, but also less hardline religious factions like the Mujahideen Army of Aleppo and various other foreign-backed militias, such as the Syria Revolutionaries’ Front of Jamal Maarouf.

The Nusra Front tried to remain neutral to avoid fitna, or internal conflict, within the Salafi-jihadi camp. But the extremism of Baghdadi’s supporters didn’t help. Golani’s calls for mediation and sharia courts to solve the dispute went unanswered, and ISIL factions captured and killed numerous Nusra Front members, including their local emir in the city of Raqqa, Abu Saad al-Hadrami. In many areas, Nusra Front factions joined the war openly, even as their leaders equivocated, further intensifying the conflict.

Open Civil War Among the Jihadis

The patience of the international al-Qaeda leadership began to wear dangerously thin after months of trying to avoid a head-on conflict that could end disastrously for both of Syria’s jihadi camps and the jihadi movement as a whole. But by February 2014, Zawahiri’s hand had been forced by the violence in Syria, and al-Qaeda finally took a firm stand against the ISIL—thereby completing the split in the global Salafi-jihadi movement.

First, in January, Zawahiri called for independent sharia mediation in Syria, in vague terms and without clearly condemning Baghdadi. But the ISIL immediately rejected precisely such a mediation attempt by the jihadi figure Abdullah al-Moheisini, even after it had been widely endorsed by Salafi-jihadi groups and intellectuals around the world. This further isolated the ISIL.

In early February, al-Qaeda issued a statement formally distancing itself from the ISIL. Three weeks later, a jihadi veteran called Abu Khaled al-Suri, who was working with Ahrar al-Sham but also entertained contacts with Zawahiri, was killed by assailants presumed to be from the ISIL. That was the final straw.

Baghdadi’s refusal of Moheisini’s mediation attempt and the killing of Abu Khaled functioned as catalysts for a jihadi rejection of the ISIL and paved the way for a formal declaration of war. In late February, the Nusra Front issued an ultimatum to the ISIL, and its leaders began heaping insults onto Baghdadi—and no one could doubt any longer that this was now a full-blown jihadi civil war.

A Watershed Year for International Jihadism

Since then, the conflict has been out in the open. At its root, it is the result of tensions that had been brewing inside the international Salafi-jihadi movement for years that finally crystallized in the rivalry between Iraqi and Syrian militant leaders.

For Syria and Syrians, it is just one of many gruesome feuds feeding into the country’s national meltdown. But for international jihadism as an ideology and as a movement, it is a watershed moment in history. The events that began on April 9, 2013, have already had enormous consequences for the group that hit the United States on September 11, 2001, and they will continue to shape its future for years to come.