The Sergeant's Daughter (1952)

In 1914, Klare Volkhardt lives with her father, a cavalry sergeant, at a German army post. She is engaged to Fritz Helbig, a solder away on a training exercise. She falls in love with Lieutenant Christian von Lauffen and, since army regulations and social differences prohibit an open romance, they meet secretly. Helbig learns of the romance, barges into von Lauffen's quarters, and discovers Klare there. A fight ensues and Helbig is tried at a court-martial for striking an officer. At his trial, he is sentenced to prison, even after von Lauffen demands to take the blame for the incident. War breaks out, Helbrig is pardoned, and von Lauffen gallops off to front line battle, with Klare praying for his safe return.