Overwhelmed by her suffocating schedule, touring European princess Ann takes off for a night while in Rome. When a sedative she took from her doctor kicks in, however, she falls asleep on a park bench and is found by an American reporter, Joe Bradley, who takes her back to his apartment for safety. At work the next morning, Joe finds out Ann's regal identity and bets his editor he can get exclusive interview with her, but romance soon gets in the way.
The retelling of June 6, 1944, from the perspectives of the Germans, US, British, Canadians, and the Free French. Marshall Erwin Rommel, touring the defenses being established as part of the Reich's Atlantic Wall, notes to his officers that when the Allied invasion comes they must be stopped on the beach. "For the Allies as well as the Germans, it will be the longest day"
A group of French soldiers, including the patrician Captain de Boeldieu and the working-class Lieutenant Maréchal, grapple with their own class differences after being captured and held in a World War I German prison camp. When the men are transferred to a high-security fortress, they must concoct a plan to escape beneath the watchful eye of aristocratic German officer von Rauffenstein, who has formed an unexpected bond with de Boeldieu.
