This film focuses primarily on the experiences of French prisoners during World War One, presenting a study of character rather than action. The prisoners reflect the diversity of French society, including Pierre Fresnay as "Boeldieu," Jean Gabin as "Maréchal," and Marcel Dalio as "Rosenthal"—each with their own resolve to escape. Numerous attempts at breaking free are shown, offering insight into the hardships they faced and how they tried to alleviate the pervasive boredom. “Boeldieu” develops an unexpected but respectful connection with the Commandant, Erich von Stroheim, another aristocrat who laments his position as a prison guard instead of a soldier. While fundamentally conventional in its structure, and with a somewhat understated conclusion, what sets it apart is how it explores the waning of a traditional class system and the fading concept of chivalrous conduct between enemies. The narrative emphasizes "Egalité," "Fraternité," and “Liberté,” portrayed with as much empathy as possible considering their dangerous situation. Gabin and von Stroheim are notably strong in their roles, as is Joseph Kosma's musical score; the concentrated attention on a small group of central figures gives the story a clear sense of direction.

Source on TMDB