Alphonse attended the School of Gentleman Cadets, where he claimed to have always won every duel. Sometime from the year 1791 to 1793, Alphonse and his friend, acting as his second, became notorious duelists for their victories. This was accomplished by a strategy where each time Alphonse faced imminent defeat, his second would intervene to kill his opponent.
One day, Alphonse and a few other duelists were challenged by the Chevalier d'Éon to duel with the skilled Assassin Arno Dorian, so that the latter could prove himself to d'Éon. Alphonse was the last to engage Arno and was confident that he would win. Contrary to his expectations, Arno managed to draw the first blood on him, thereby seizing victory and causing the judge to order the match to have ended. Alphonse's second stepped as usual, however, with Alphonse ignoring the judge's warnings and shouting that he "would never yield". In self-defense, Arno was forced to slay Alphonse and his second.