July 2011 jihadists keen to settle scores with officers who had crushed their revolt in the late 1990s killed the NTC’s commander-in-chief, Abdel Fattah Younis, who came from a powerful Arab tribe in the Green Mountains. In June 2013 the Transitional Council of Barqa (the Arab name for Cyrenaica), a body primarily comprised of Arab tribes, declared the east a separate federal region, and soon after allied tribal militias around the Gulf of Sirte took control of the oilfields.