Today the Islamic State released a short video that showed the execution of Henning. The video opens with a news clip that announces Britain's involvement in US-led airstrikes against the Islamic State. After the news video is played, the words "Another message to America and its allies" is displayed.
Henning, whose hands are cuffed behind his back and is wearing an orange shirt and pants, is shown kneeling in the desert. A masked Islamic State fighter dressed in black and wielding a knife stands to the hostage's side.
Henning issues a brief statement before he is killed.
"I am Alan Henning. Because of our Parliament's decision to attack the Islamic State, I, as a member of the British public, will now pay the price for that decision," he says.
His jihadist executioner, who is certainly the same man who killed two other Americans and a British citizen in the same fashion in previous videos, then speaks.
"The blood of David Haines was on your hands Cameron. Alan Henning will also be slaughtered, but his blood is on the hands of the British Parliament," the jihadist says, and then proceeds to behead Henning.
Henning's bloody body is subsequently displayed, with his head placed on his back.
The executioner is then shown with American hostage Peter Edward Kassig, who, like Henning, is also wearing an orange shirt and pants and is kneeling on the ground with his hands bound behind his back.
"Obama, you have started your aerial bombardment in Sham [Syria], which keeps on striking our people. So it is only right that we continue to strike the necks of your people," the jihadist says, threatening Kassig.
Kassig is a former US Army Ranger who founded Special Emergency Response and Assistance, an aid group that operated in Syria and Lebanon. The group "temporarily ceased its operations" sometime after Kassig was kidnapped, according to a statement on SERA's home page.
Henning is the fourth Western hostage executed by the Islamic State since the US opened its air campaign against the group in Iraq on Aug. 7.
Kassig may only have a few weeks to live unless US forces are able to identify his location and rescue him. If the past is any indication, the Islamic State will execute Kassig within the next two to three weeks. The Islamic State released its first execution video, of American James Wright Foley, on Aug. 19, and in it threatened Steven Joel Sotloff, another US citizen. The video of Sotloff's beheading was released on Sept. 2, and British citizen David Cawthorne Haines was threatened. Haines' beheading video was released on Sept. 13, and Henning was threatened in that video.
The Islamic State is also known to be holding British journalist John Cantlie and an unidentified female American citizen. Cantlie has been featured in a series of Islamic State videos called "Lend Me Your Ears," which discusses the jihadist group's perspective on the US-led military intervention in Iraq and Syria.