Victor François de Montchenu came from one of the oldest families in the Dauphiné, and one long devoted to military service. He was admitted to the Ecole des chevaux-légers as a child and in 1775 became sous-lieutenant of the "régiment d'infanterie du Roi" (King's Infantry Regiment), at a time when officer ranks were reserved for sons of the noble families. He was a captain in this corps during the Nancy affair, finding himself beside André Désilles when the latter died by throwing himself in front of a cannon in a vain hope of stopping the battle between the mutineers and the troops of de Bouillé.