Hashim al-Sheikh

Hashim al-Sheikh , also known by his nom de guerre Abu Jaber Sheikh , is a Syrian rebel commander and senior leader of Hay'at Tahrir al-Sham. Previously a senior commander in Ahrar al-Sham, he directed its merger with other Islamist groups to form Hay'at Tahrir al-Sham. and later received a bachelor's degree in mechanical engineering at the University of Aleppo. After this, he worked at the Defence Factories near as-Safira. His Islamist activities and opposition against the Ba'athist government led to him being arrested by the Syrian government several times. In 2005, he was imprisoned in the Sednaya Prison, infamous for holding a number of other Salafist prisoners who were later released. He resigned and was replaced by Muhannad al-Masri (Abu Yahia al-Hamawi) in September 2015. An Ahrar al-Sham spokesman described Abu Jaber's leadership as the "hardest" period of the group.

On 15 February 2016, during the northern Aleppo offensive, 8 rebel factions pledged allegiance to Abu Jaber and established the Army of Aleppo to fight the Syrian Armed Forces and the Syrian Democratic Forces, including the Army of Revolutionaries. Abu Jaber is one of the three surviving founding leaders of Ahrar al-Sham.

On 1 October 2017, Abu Jaber resigned from his position as the general commander of Tahrir al-Sham, being replaced by Ahmed al-Sharaa (also known as Abu Mohammad al-Julani). Abu Jaber took another position as the head of HTS's Shura council.