The death of Abu Muhammad al-Adnani al-Shami, official spokesperson of ISIS, on August 30 dealt a harsh blow to the organization. Al-Adnani was killed in international coalition airstrikes while in the city of al-Bab in the eastern countryside of Aleppo, for the significant role he played in the Islamic State (ISIS) since the organization was first announced in June 2014. Al-Adnani was appointed as its official spokesperson, and it was predicted he might be named Emir of Syria.

Al-Adnani’s death shows that coalition airstrikes have clearly penetrated ISIS and reached ISIS’s top personnel, raising the possibility of targeting Abu Bakr al-Baghdadi, the leader of the organization itself. Yet ISIS has shown itself to be remarkably resilient. According to intelligence reports, the organization has a plan to find a replacement leader if al-Baghdadi is killed. Al-Baghdadi, is also likely to meet with the Shura Council of ISIS in the next few days to select a replacement for al-Adnani from among the available candidates.

Turki al-Binali is one of the top candidates for al-Adnani’s position. Al-Binali is the second most influential person within ISIS, after al-Baghdadi. Al-Binali is a Bahraini national born in 1984, and goes by several names including Abu Sufyan al-Sulami, Abu Hudhayfa al-Bahrayni, and Abu Human al-Athari. He is a senior Islamic scholar within ISIS. Al-Binali was detained several time during his university studies in the United Arab Emirates, and ultimately deported back to Bahrain, where he was detained for a period of seven months in 2007. Following his release, he studied Sharia under senior leaders and theorists in the jihadist movement, including Muhammad al-Maqdisi. Al-Binali joined ISIS in Syria in early 2013, and soon became the Grand Mufti of the organization, given his strong rhetorical skills and speaking abilities. Al-Binali began his career by laying the foundations of ISIS’ work, and then by heading the organization’s Research and Fatwa Department, which is the source of many fatwas, including one that legalized the rape of Yazidi women. Al-Binali served as negotiator in the efforts to free American hostage Peter Kassig, with al-Binali’s former teacher, Abu Muhammad al-Maqdisi, acting as a go-between.

In order to lead the operation, al-Binali relied on the legitimacy of Abu Bakr al-Baghdadi, an early affiliate of al-Qaeda under Osama Bin Laden’s leadership. Al-Binali had written a book titled Extend Your Hand in Allegiance to al-Baghdadi, in which he explained al-Baghdadi’s claim to the caliphate.

In contrast, some predictions point to the possibility that Moussa al-Shawakh could be a second candidate in line for al-Adnani’s position in ISIS. Better known by the name Abu Luqman, he was appointed as the first governor of Raqqa province, which ISIS has claimed as its capital. Al-Shawakh is a Syrian national from the village of al-Sahl in Raqqa. He was born in 1973, and graduated from the University of Aleppo with a degree in Law. Early on, he had a Sufi orientation, given his close relationship with Abu Qaqa al-Suri, who recruited many young men to fight against American troops in Iraq in 2013. It was later discovered that he had ties with the Syrian regime. Al-Shawakh was imprisoned several times by the regime, and was held in Sednaya prison on the last occasion, where he was introduced to theorists of Salafi Jihadism. The Syrian government released Al-Shawakh at the beginning of the Syrian revolution in 2011, along with many other known extremist, in hopes that they would harm the opposition and make it more extremist. He has used several names, including Abu Abdullah al-Gharib and Abu Ayyub al-Ansari. As the armed struggle of the Syrian revolution began, he started going by the name Abu Luqman, as the Emir of the Nusra Front and a close associate of al-Qaeda’s branch in Iraq. After armed forces of the opposition seized the city of Raqqa in March 2013, Abu Luqman gained control of the oil wells and wheat stores in the province and sold them to the Syrian regime, which was a financial boon, allowing the group to fund itself.

When the Islamic State of Iraq and Syria was announced, Abu Luqman was among the first to declare his allegiance to al-Baghdadi. He split from al-Nusra Front—a branch of al-Qaeda in Syria—and later appointed his closest associates to different sections of ISIS across Syria.

Abu Luqman is known for being extremely brutal, and for his sadistic torture methods, according to the testimonies of former ISIS detainees. He ordered the kidnapping of activists, leaders, and members of the Free Syrian Army, under the accusation that they were working for the West. He also ordered the execution of Abu Saad al Hadrami, the Emir of the Nusra Front in Raqqa, after al-Hadrami was kidnapped.

In 2013, Abu Luqman was appointed as governor of the eastern countryside of Aleppo. With his might and skill, he stopped factions of the Syrian opposition from extending into regions under ISIS control, and strengthened ISIS’ influence in these regions. At the beginning of 2015, he stopped using the name Abu Luqman, and instead began going by Abu Ayoub, as the general supervisor of Sharia camps to train ISIS leaders. According to local sources, Abu Luqman’s desire for power played a role in the operation to kill al-Adnani: al-Adnani had been sent to the countryside east of Aleppo to restrict Abu Luqman’s influence and strip him of his authority.

Jordanian national Omar al-Mahdi Zeidan, who also goes by Abu al-Munther al-Urdoni, is another candidate to replace al-Adnani. He is one of the most prominent theorists of Salafi Jihadism. He has a bachelor’s degree in Islamic Sharia‘ from universities in Jordan, where he was also imprisoned in the mid-1990s, along with many other Salfi leaders including Abu Musab al-Zarqawi, whom Osama bin Laden called the Emir of al-Qaeda in Iraq, and Abu Muhammad al-Maqdisi, another Jordanian Salafi theorist. Al-Maqdisi was released from prison in 1999 by royal pardon, and joined the ranks of ISIS in Syria alongside Abu al-Munther in 2013. He was subsequently appointed as a Sharia judge, and then governor of ISIS’ Judiciary Department.

Feras Hanoush is an activist from Raqqa, a former doctor with Médecins Sans Frontières in Syria, and a member of Raqqa is Being Slaughtered Silently.

Image: Photo: Bullets lie next to a gun at a Sinjar Resistance Units (YBS) check point, a militia affiliated with the Kurdistan Workers Party (PKK), in the village of Umm al-Dhiban. REUTERS/Goran Tomasevic