(CNN)In the early hours of Thursday morning, the head of ISIS died during a US raid in northwest Syria just as the extremist group was in the midst of a revival.
Abu Ibrahim al-Hashimi al-Qurayshi killed himself and his family after igniting a bomb at the beginning of the operation, according to a senior Pentagon official.
Qurayshi succeeded ISIS founder Abu Bakr al-Baghdadi in 2019 after his demise. When Qurayshi took over the organization, the vast swathes of territory the group controlled -- an area larger than the size of the United Kingdom at its peak -- had largely vaporized. Observers dubbed him a Caliph without a Caliphate. Yet he sought to reinvigorate the organization.
In recent months, he oversaw a resurgence of ISIS in various parts of Syria, Iraq and Lebanon. Iraq reported an uptick in violence linked to ISIS. In the Kurdish-controlled northeastern part of Syria, the group staged a lethal days-long attempted jail break in a bid to free ISIS members. Hundreds of inmates, including children, died. Scores of Kurdish fighters also perished in the clashes.
In Lebanon, multiple regional and local reports have indicated that the group has been recruiting scores of members from the northern city of Tripoli, one of the areas hardest hit by the country's devastating economic crisis.
Throughout it all, Qurayshi -- who was known by several aliases -- kept a low profile, much like his predecessor. The US Rewards for Justice program offered a reward of $10 million for information about him. His history in the organization is also murky. But snippets from interviews with ISIS prisoners paint a picture of a man with a dark past as a member of Baghdadi's inner-most circle.
Qurayshi became a "religious scholar" with al Qaeda in Iraq, before the group rebranded itself as the Islamic State. In 2014, he "helped drive and justify the abduction, slaughter, and trafficking of the Yazidi religious minority in northwest Iraq," the Rewards for Justice notice says.
Much of the Yazidi community lived in an area close to what some analysts believe was Qurayshi's home town of Tal Afar in northern Iraq. In 2014, after ISIS had taken Tal Afar and Mosul, the group enslaved thousands of Yazidi women and children and murdered thousands of Yazidi men, in what the United Nations has called a genocide.
The Commission for International Justice and Accountability, an NGO that investigates and gathers evidence of major international crimes such as terrorism, said Qurayshi was "one of the key architects of the Islamic State slave trade in Yazidi women and children."
"He personally enslaved and raped captive women," said Nerma Jelacic, the group's deputy director.
Counter-terrorism expert Daniele Raineri has noted that he was "the deputy who managed to spend the years since 2010 almost totally under the radar." But when others in the ISIS hierarchy were taken or died in battle, he became one of the group's leading ideologues.
In a 2018 interview with Saudi-owned al Arabiya, a senior ISIS detainee in Iraq, Ismael al Eithawi called Qurayshi "the most prominent of Baghdadi's surrounding circle."
A 2018 internal ISIS document repeatedly describes Qurayshi as "the deputy" to Baghdadi. He died in an operation similar to that which killed Baghdadi. And it is yet unclear if the operation will stem the group's resurgence or if the cycle of extremist violence will continue undeterred.
ISIS has not acknowledged his death and it's as yet unclear who may replace him. Few if any of Baghdadi's inner circle are thought to be still at large.