Pictures of members of the brigade have flooded social media in recent years and a video of al-Mazwagi, who is the first British jihadi known to have died in Syria, lifted the lid on life as a terrorist
Among the brigade’s most notorious alumni is Abu Omar al-Shishani, one of the most feared military commanders of the Islamic State of Syria and Iraq
Al-Shishani, a red-bearded ethnic Chechen and former sergeant in the Georgian Army – became the commander of the brigade, which was initially aligned with al-Qaeda’s Jabhat al-Nusra.
The group merged with other jihadists in March 2013 to form Jaish al-Muhajireen wal-Ansar [Army of Emigrants and Supporters], a larger and more structured group with a religious council.
In May 2013, Shishani switched to supporting the Islamic State of Iraq and Syria and was named commander of the northern sector of Syria, around Aleppo.
A video obtained and published by Channel 4 in 2013 shows life as an extremist in Syria – likely the experience of Emwazi before he went to fight for Islamic State.