The Duellists is based on a story by Joseph Conrad, variously titled The Duel and The Point of Honour. Keith Carradine and Harvey Keitel play officers in Napoleon's army -- D'Hubert and Feraud, respectively -- who spend their off-hours challenging each other to bloody duels.
This goes on for nearly 16 years, with neither man showing any inclination of calling a truce. The final clash finds the gentlemanly D'Hubert getting the upper hand of the obsessed Feraud -- but that's not quite the end of the story. The Duellists was the debut feature for director Ridley Scott; it won the Cannes Film Festival prize for Best First Film.