On 19 August, 2014, the world watched in horror as a video uploaded on YouTube showed the beheading of American journalist James Foley.
In the video, Foley — in an orange jumpsuit — was shown kneeling in the desert, next to an Islamic State terrorist with a knife to his throat. The militant was dressed all in black, in such a way that only his eyes were visible.
After a statement by Foley, the masked IS terrorist was shown apparently beginning to cut at the neck of the captive. The video faded to black before the beheading was completed. The next shot appeared to show the captive lying dead on the ground, his head decapitated.
At the end of the video, the terrorist showed a second man, who was identified as another American journalist, Steven Sotloff, and warned that he could be the next captive killed.
Just two weeks after the video horrified the world, yet another video was released, showing the beheading of Sotloff by the same masked IS militant.
It was because of this cold-blooded brutality that the IS terrorist Mohammed Emwazi, nicknamed 'Jihadi John' by the media, became one of the most infamous and hated people in the world.
Emwazi's nickname 'Jihadi John' was based on nicknames freed hostages said they gave their British-sounding captors, a reference to Beatles member John Lennon.
He horrified the world with videos of brutally beheading hostages. In most videos, he acted as a narrator, taunting the West and promising an IS although the videos don't make it clear whether or not he carried out all of the actual killings.
But his videos, with sneering taunts at the West, also served as a recruiting tool for those drawn to the dark, bloody world of extremism.
Emwazi's brown eyes peering out from behind a black balaclava and his London accent became the first contact many around the world had with the terror group Islamic State, although the extremists carried out other mass killings, rape and enslavement in their march across Iraq and Syria.
Born in Kuwait, Emwazi grew up in Britain. He spoke English in his videos, making the message even easier for the world to understand.
"You're hearing it in your own language, so the threat sounds all the more menacing," Raffaello Pantucci, the author of We Love Death As You Love Life: Britain's Suburban Terrorists and the director of international security studies at Britain's Royal United Services Institute, had said.
"It speaks to the audience and says, you know, 'We are you...You think we're this alien thing but actually no, we're from within your very communities,'" Pantucci had added.
Emwazi soon became one of the West's top targets after IS leader Abu Bakr al-Baghdadi and his other lieutenants.
In November 2014, a 15-minute video posted online showed Islamic militants beheading at least 14 men. Emwazi again appeared in the video and according to Islamic State, the victims were pilots and officers loyal to Syrian President Bashar al-Assad. American hostage Peter Kassig was one of the victims.
Jihadi John was identified as Mohammed Emwazi in February 2015. The Washington Post and the BBC, which had first identified the masked man in the video as Emwazi, had said he was born in Kuwait, grew up in west London and studied computer programming at the University of Westminster. The university had confirmed that a student of that name graduated in 2009.
The news outlets had said Emwazi was known to British authorities before he travelled to Syria in 2012.
Emwazi had also traveled to Tanzania with two other men after leaving university in 2009, but was deported and questioned in Amsterdam by British and Dutch intelligence services, who had suspected him of attempting to join al-Shabaab militants in Somalia.
In 2010, Emwazi had accused the British intelligence services of preventing him from traveling to Kuwait, where he planned to work and marry. CAGE, a London-based advocacy group that counsels Muslims in conflict with British intelligence services, had quoted an email Emwazi had sent saying, "I had a job waiting for me and marriage to get started. But now I feel like a prisoner, only not in a cage, in London."
Emwazi was reportedly killed in a drone strike by the US on 12 November, 2015. The US military had said at the time that it was "reasonably certain" he had been killed in the strike.
The death of Mohammed Emwazi aka Jihadi John was confirmed by the IS on Tuesday. In its online magazine Dabiq, the terror group said Emwazi was killed on 12 November "as the car he was in was targeted in a strike by an unmanned drone in the city of Raqqa, destroying the car and killing him instantly."
With inputs from agencies