Alphonse and a fellow dueler attended the School of Gentleman Cadets, where according to himself and his fellow dueler, he was always first and always won the duels. Around 1791-1793, Alphonse and his friend (acting as his second during duels) became a known dueler around Paris, always winning. However, every time Alphonse would be defeated, his second would step in and unfairly help him in killing the enemy dueler.
Alphonse and a few other duelers were challenged by the Chevalier d'Éon to duel with the skilled Assassin Arno Dorian, so the latter could prove himself to d'Éon. Alphonse was the last to duel Arno, being confident that he would win. Arno managed to draw the first blood on Alphonse, winning and causing the judge to order them to stop dueling. Alphonse's second stepped in however, with Alphonse ignoring the judge's warnings and claiming that he "would never yield". Arno was then forced to kill Alphonse and his second.