After he finished writing Clouds of Glory: The Life and Legend of Robert E. Lee, prolific author Michael Korda, who spent decades as the distinguished editor-in-chief of Simon & Schuster, immediately began contemplating his next immersive book project, hoping it would be as weighty. His late wife, Margaret, suggested he chronicle WWII’s dramatic Dunkirk evacuation. Korda took her advice and for the next three years he dived deep into the saga, an endeavor that “in fact, turned out to be more work than the last subject,” he says, and culminated in Alone: Britain, Churchill, and Dunkirk: Defeat into Victory (Liveright, Sept.).

This oft-misunderstood event, which lasted from May 26 to June 4, 1940, was a stark turning point in the war. Trapped by the Germans on a northern French beach, the fate of the British Expeditionary Force seemed grim, capture imminent. Then, on the cusp of calamity, Hitler made the perplexing decision to halt his troops, giving the British time to hatch an escape plan. Dubbed Operation Dynamo, some 350,000 Allied soldiers crossed the Channel to safety in England. amid a barrage of bombs and shelling. Buoying confidence and hope, Dunkirk became a fierce symbol of British resilience, fortifying the wavering faith that Britain could indeed bring Germany to its knees. “There was a great change in public and personal opinion,” Korda points out. While Alone illuminates the 10-day ordeal in vivid detail,Korda also places Dunkirk in context. “You think you know a lot about something, but as I began to delve into this, I realized there was a lot I didn’t know. If we don’t talk about what led up to Dunkirk, then it’s a truncated history,” he explains. For Korda, it was imperative to begin at the inception of WWII.

Korda endeavored to look at how the war came about, examining “the mistakes, desires, ambitions, and innermost thoughts of everyone involved— including the Germans,” he says. ”One of the problems of the history of our time is that we tend to see the war through Churchill’s eyes, and that’s not a 360-degree way of viewing the outbreak. Many people get short shrift.” In Alone, Churchill’s controversial predecessor, Neville Chamberlain, gets the limelight, as do a slew of government and armed forces brass, and Hitler, whose skepticism of naval power helped cost him the war.

Korda, who grew up in England—admittedly in the midst of great privilege—was just seven at the time of the Dunkirk evacuation. But he brings a bit of levity to Alone by peppering it with lighthearted memories of how his own celebrated moviemaking family was affected by WWII. “Showing how people kept going on under the threat of Germany,” he says. “I could only do that by injecting myself into the story.”

Today, 2–2:30 p.m. Michael Korda signs Alone in the Liveright booth (1620).