Jihadi John

Mohammed Emwazi was a Kuwaiti–born British militant believed to be the person seen in several videos produced by the Islamist extremist group ISIL showing the beheadings of a number of captives in 2014 and 2015. A group of his hostages nicknamed him "John" since he was part of a four-person terrorist cell with English accents whom they called "The Beatles"; the press later began calling him "Jihadi John".