Obviously the history behind the movie Dunkirk (2017) is from actual events of WW2. But what about the specific characters whose stories we watch converge? Are they based on actual events?
The characters are fictional...
All the characters in Dunkirk are made up, though Nolan did his research in creating them. He and Joshua Levine, a historian who helped work on the script, consulted veterans before filming the movie, according to The New York Times.
so the specific events are amalgams of real experiences and stories...but there is at least one analogous story..that of Farrier.
In researching the Dunkirk true story, we discovered that while the character Farrier is not directly based on an actual person, his experience most closely resembles that of Alan Christopher "Al" Deere (pictured below), a New Zealand Spitfire pilot. Deere's plane was hit in the cooling system by the rear gunner of a German Dornier, and like Tom Hardy's character in the movie, Deere crash-landed on the beach. He landed wheels up on the water's edge and gashed his eyebrow in the process.
Are the main characters in the movie based on real people?
No. Much in the same vein as Steven Spielberg's Saving Private Ryan, director Christopher Nolan chose to create fictional characters for his film. Some were inspired in part by actual eyewitness stories but were not slavishly based on real people. Nolan explained that he had first worked out "a precise mathematical structure" for the story, which involved telling it from three perspectives: the land (soldiers on the beach), the sea (boats assisting in the evacuation), and the air (fighter planes). The best way to maintain that structure was to create fictional characters who could be utilized freely for the greatest benefit of the story.
In terms of accuracy, it rates pretty highly. There are no big, glaring historical whoppers. The characters whom Nolan invents is to serve his narrative purposes are realistic, and his scenes depict genuine events or hew close to firsthand accounts. And why not, since fiction could hardly outdo the drama and emotion of the reality? Nolan made clear that he intended the film to be a kind of history of an experience, and he succeeds about as well as any filmmaker could in conveying what it might have felt like to be on that beach.
For example, one theme that’s repeated across the reminiscences of WWII veterans on all sides is the stark animal terror of being subjected to unopposed air assault. If artillery barrages and shellshock were the defining experiences of World War I, strafing and bombing and resultant mental breakdown were arguably the defining experiences of World War II. And several scenes in the film must be as near a manifestation of that experience as can be safely had at the multiplex.
But, of course, Nolan didn’t set out to present history the way scholars do it. Historians’ careers rest on perfect accuracy, and nuance and complication are prized—even at the high cost of turning away nonprofessional readers. So, Nolan makes choices in assembling, and sometimes inventing, his facts that academics would not.
Commander Bolton is no particular RN officer, but in him we see a reflection of especially Commander James Campbell Clouston, and to some extent Captain William Tennant.