Partially inspired by stories told to Mendes by his paternal grandfather Alfred about his service during World War I,[7] the film takes place after the German retreat to the Hindenburg Line during Operation Alberich, and follows two British soldiers, Will Schofield (George MacKay) and Tom Blake (Dean-Charles Chapman), in their mission to deliver an important message to call off a doomed offensive attack.

Mark Strong, Andrew Scott, Richard Madden, Claire Duburcq, Colin Firth, Adrian Scarborough, and Benedict Cumberbatch also star in supporting roles.

The project was announced in June 2018, with MacKay and Chapman signing on in October and the rest of the cast joining the following March.

The film received numerous accolades including ten nominations at the 92nd Academy Awards, for which it won three, for Best Cinematography, Best Sound Mixing, and Best Visual Effects.

On 6 April 1917, aerial reconnaissance has observed that the Imperial German Army, which has pulled back from a sector of the Western Front in northern France, is not in retreat—as had been supposed—but has made a strategic withdrawal to the new Hindenburg Line, where they are waiting to overwhelm the British with artillery.

In the British trenches, with field telephone lines cut, two young British lance corporals, William Schofield, a veteran of the Somme, and Tom Blake, are ordered by General Erinmore to carry a message to Colonel Mackenzie of the 2nd Battalion of the Devonshire Regiment, calling off a scheduled attack the next morning that would jeopardise the lives of 1,600 men, including Blake's brother Joseph, a lieutenant.

In an underground barracks, they discover a tripwire set by the Germans, which is promptly triggered by a rat; the explosion almost kills Schofield, but Blake saves him, and the two escape.

Taking Blake's rings and dog tag, as well as Erinmore's letter, he is picked up by a passing British unit.

[8] Tom Holland was reported to be pushing for a lead role in the film in September 2018 but ultimately was not involved as he was contractually obligated to do reshoots for Chaos Walking in April 2019.

[13] That same month, Benedict Cumberbatch, Colin Firth, Mark Strong, Richard Madden, Andrew Scott, Daniel Mays, Adrian Scarborough, Jamie Parker, Nabhaan Rizwan, and Claire Duburcq joined the cast in supporting roles.

"[15] In December 2019, Mendes stated that the writing involved some risk-taking: "I took a calculated gamble, and I'm pleased I did because of the energy you get just from driving forward (in the narrative), in a war that was fundamentally about paralysis and stasis."

[18][19] Although many media accounts have referred to the story as being told in only one shot,[20][21] the screen does cut to black one hour and six minutes into the film, when Schofield is knocked unconscious, and fades in upon his regaining consciousness after night has fallen.

Arri provided him with a prototype of the Mini LF two months before filming was set to begin, and two more cameras a week before.

[24] Filming began on 1 April 2019[citation needed] and continued through June 2019 in Wiltshire, Hankley Common in Surrey and Govan, as well as at Shepperton Studios.

[25][26][27][28] Concern was raised about filming on Salisbury Plain by conservationists who felt the production could disturb potentially undiscovered remains, requesting a survey before any set construction began.

Crew members on set, including two grips, had to dress as soldiers and pass in front of the lens as the camera pulled back in order to get the "complex choreography" of the scene executed properly.

In conclusion, MacKay described the shot as a "reflection of the entire film", while going on to say that "It's a very simple journey through massive difficulty, but there's the notion that it has to get done ...

The website's critical consensus reads, "Hard-hitting, immersive, and an impressive technical achievement, 1917 captures the trench warfare of World War I with raw, startling immediacy.

"[51] Metacritic assigned the film a weighted average score of 78 out of 100 based on 57 critics, indicating "generally favorable reviews".

[45] Several critics named the film among the best of 2019, including Kate Erbland of IndieWire[53] and Sheri Linden of The Hollywood Reporter.

[54] Writing for the Hindustan Times, Rohan Naahar stated, "I can only imagine the effect 1917 will have on audiences that aren't familiar with the techniques Sam Mendes and Roger Deakins are about to unleash upon them.

He agreed the film was a "mind-boggling technical achievement" but did not think it was that spectacular overall, as Mendes's style with its impression of a continuous take "can be as distracting as it is immersive".

"[58] Meilan Solly of the Smithsonian said "the film has more than fulfilled this goal (elevate World War I cinema to a previously unseen level of visibility), wowing audiences with both its stunning visuals and portrayal of an oft-overlooked chapter of military lore.

[68][69] The film was inspired by Operation Alberich, a German withdrawal to new positions on the shorter and more easily defended Hindenburg Line that took place between 9 February and 20 March 1917.

Instead, the majority of black troops who participated in the British war effort served in their own colonial regiments from Africa and the West Indies.