Based On True Story!
I checked the Wikipedia and noticed, that the story is actually based on real story.
http://en.wikipedia.org/wiki/The_Duellists#Historical_basis
The Conrad short story evidently has its genesis in the real duels that two French Hussar officers fought in the Napoleonic era. Their names were Dupont and Fournier, whom Conrad disguised slightly, changing Dupont into D'Hubert and Fournier into Féraud.
As a young officer in Napoleon's Army, Dupont was ordered to deliver a disagreeable message to a fellow officer, Fournier, a rabid duellist. Fournier, taking out his subsequent rage on the messenger, challenged Dupont to a duel. This sparked a succession of encounters, waged with sword and pistol, that spanned decades. The contest was eventually resolved when Dupont was able to overcome Fournier in a pistol duel, forcing him to promise never to bother him again.
They fought their first duel in 1794 from which Fournier demanded a rematch. This rematch resulted in at least another 30 duels over the next 19 years in which the two officers fought mounted, on foot, with swords, rapiers, and sabres.