Officially, the 39-year-old Taha Subhi Falaha, better known as Abu Mohammed al-Adnani, was spokesman for the so-called Islamic State: a vitriolic but compelling rhetorician for the caliphate whose imprecations—against America, the Shia, insufficiently pious Muslims and eventually al Qaeda—earned him the nickname “attack dog.”

Now he’s a dead one, according to the organization he served.

In a statement, the ISIS propaganda agency Amaq said he was “martyred while surveying the operations to repel the military campaigns in Aleppo,” in Syria.

The Pentagon is being cautious, or perhaps a little coy. A senior defense official said “coalition forces conducted an airstrike in al-Bab, Syria,” and the target was Adnani. Although it is “still assessing the results of the strike... Al-Adnani’s removal from the battlefield would mark another significant blow to” the terror franchise, Pentagon Press Secretary Peter Cook said in a statement this evening.

Adnani would be by far the most important ISIS leadership target yet eliminated by coalition forces.

Unofficially, he ran “all of Syria” for ISIS, according to Abu Khaled, a pseudonymous defector from the organization’s FBI-like amn al-dawleh security service, one of four main intelligence branches tasked with ensuring that no threats could ever emerge to the Islamic State from within.

Adnani’s primary concern, at least as of the last two years or so, was overseeing the exportation of savagery in the form of foreign terrorist attacks planned and perpetrated by ISIS central command in Syria. He also egged on those who might otherwise be “inspired” by its world-historical, messianic vision of first restoring the Levant and Mesopotamia to a purer, 7th-century version of Islamic rule and then, God willing, conquering the world. This assessment is shared by Cook, who noted in his press release, that Adandi was the “principal architect of [ISIS’s] external operations” and “coordinated the movement of [ISIS] fighters, directly encouraged lone-wolf attacks on civilians and members of the military and actively recruited new [ISIS] members.”

What distinguished Adnani from other ISIS leaders was his personal and professional closeness to Abu Musab al-Zarqawi, the father of the organization now known as ISIS.

Adnani was a veteran and a survivor from the early days, one of three dozen or so jihadists recruited by the murderous Jordanian zealot al-Zarqawi in 2002. At the time Zarqawi was still running an independent terrorist group known as Ansar al-Islam, which he took control over while bivouacked in the mountainous region of Iraqi Kurdistan. Interestingly, Zarqawi recruited Adnani in Aleppo, likely with the tacit approval (if not connivance) of Bashar al-Assad's mukhabarat or intelligence service, which would spend close to a decade hosting all manner of foreign jihadists, including and especially those belonging to Zarqawi's network, prior to their transfer into Iraq.

After Baghdad fell to U.S.-led forces in the ill considered invasion of 2003, Zarqawi and his coterie, including Adnani, took advantage of the chaotic occupation and established themselves as a ferocious part of the resistance. They raised money with kidnappings and their gained international infamy by beheading foreigners on video tape. After Zarqawai pledged allegiance to Osama bin Laden, he and Adnani and others in his group became known as al Qaeda in Iraq.

Zarqawi was killed by U.S. airstrikes in 2006. A year earlier, Adnani himself had been captured in Anbar province. He was imprisoned in Camp Bucca and other U.S.-run facilities for about five years. This theater-wide internment operation administered by the Pentagon seems in retrospect a finishing school for ISIS’s upper cadres. Adnani was one of the graduates. So was Abu Bakr al-Baghdadi, the self-proclaimed caliph of the so-called Islamic State.

Zarqawi and Adnani had always foreseen that the jihadist war they fought against the American occupation in Iraq would bleed into next-door Syria and eventually take on apocalyptic dimensions in the Aleppo suburb of Dabiq, which is now the name of ISIS’s English-language propaganda magazine.

Binnish, Idlib was Adnani’s birthplace, and if ISIS’s Amaq News Agency is to be believed, Aleppo is now the site of his demise. He reportedly was killed on the outskirts of al-Bab where ISIS’s amn al-kharjee, or the foreign intelligence branch for which he was responsible, is headquartered.

Adnani is said to have maintained several residences in al-Bab, although the circumstances of his death, the party responsible, much less independent confirmation of its veracity, are as yet unavailable.

As for the attack dog’s verbal style, his arrogance and presumption seemed premised on the longevity of his project and, indeed, his own life.

When, in 2013, ISIS formally split from al Qaeda, the attack dog turned rabid against his erstwhile patron, al Qaeda leader and bin Laden successor Ayman al-Zawhiri, who had ordered Adnani’s group to withdraw from Syria and limit its purview to Iraq. Zawahiri wanted them to leave the holy war in the Levant to the nativist insurgency known as Jabhat al-Nusra.

Adnani, perhaps emboldened by his own Syrian lineage, baldly responded that God’s will superseded that of the aged Egyptian doctor, now leading a somewhat desiccated jihad from the hideaway caves of Waziristan.

More damningly, Adnani said, Zawahiri was de facto legitimating the tawaghit, or tyrannical, principles of contemporary Middle Eastern nation-states cobbled together by the Sykes-Picot agreement. The rising Islamic State abided by no such boundaries, as would be demonstrated in the physical razing of them with bulldozers in June 2014.

Adnani shared in the late Zarqawi’s genocidal hatred of Shia Muslims and so also took the opportunity of scandalizing Zawahiri, accusing him of playing it too safe by not attacking the mothership of Shiism, Iran. “Let history record that Iran owes al Qaeda invaluably,” said Adnani. It was his way of calling the leader of al Qaeda a sellout.

No doubt Adnani’s most famous communiqué was the one delivered in September 2014, about year before the atrocities unleashed on the Bataclan theater in Paris. He encouraged Muslims living in the West to murder any “disbelieving American or European—especially the spiteful and filthy French” they came across, be it by smashing the infidel’s head in with a rock or running over him with a car, as Mohamed Lahouaiej-Bouhlel, did to 86 people, Muslims included, in Nice on Bastille Day.

The uptick in ISIS terrorism internationally, “lone wolf” or coordinated in nature, has been largely attributed to Adnani’s casting call for such invisible soldiers of the caliphate fanned across the globe.

One of his last messages was also his most defensive. “Do you, O America,” he said in May 2016, “consider defeat to be the loss of a city or the loss of land? Were we defeated when we lost the cities in Iraq and were in the desert without any city or land? And would we be defeated and you be victorious if you were to take Mosul or Sirte or Raqqa or even take all the cities and we were to return to our initial condition? Certainly not!”

Many analysts interpreted this as a pre-emptive morale booster for the ISIS rank-and-file in light of the coming loss of major population centers, if not the formal inauguration of the next phase of ISIS war-making: against the West, in the West.

Regardless, the legacy Adnani leaves is one of widows and orphans, from California to Orlando, and Baghdad to Jakarta.

—with additional reporting by Nancy Youssef