Beau Geste-1939-William A Wellman

Three boys grow up together in a wealthy family. As a child, one of the boys overhears his mother discussing the sale of the "Blue Sapphire," a jewel that belongs to her family. It is replaced with a fake and the household continues on. Many years later the family is in financial trouble and discuss selling the "Blue Sapphire." Knowing it is a fake and wanting to save their mother from shame, it is stolen during a blackout moments before it would have been revealed. The boys are given until morning to own up, but when morning comes the eldest has left a note confessing and has gone to join the Foreign Legion. His brothers, knowing his sacrifice, also leave notes confessing and join the Legion. The three brothers are stationed together until the middle one is sent away to separate the three. The general in charge of the outpost is considered a madman with no respect for the dead. His plan is to prop dead soldiers up on the walls so the Arabs will think they have lots of men. When one of the brothers is killed the other fights to have his body respected and buried instead of used and shot up. With the middle brother's return and subsequent death just moments before a final attack, the youngest is the only one who makes it safely home.