Not your normal war film with bullets, bombs every 5 minutes but great to watch and the acting is superb, as we grew up in the Tilbury Docks area, Essex, my mother would tell us how she saw POWs being returned after WWII by ship in the docks from Japanese prisoner of war camps, some prisoners were permanently bent and could hardly walk as they were shut in cages for years, others were just skin & bones.
The film won loads of awards and Alec Guinness won the academy award for the best actor, the marching song haunts me to this day.