Vérac entered the Musketeers of the Guard in 1757. In 1761 he became Aide-de-camp of his father-in-law during the Seven Years' War. He was wounded in the arm at the Battle of Villinghausen by the same cannon ball that killed his father-in-law. In 1767 he was appointed Colonel of the "Régiment de Grenadiers de France". In 1770 he was promoted to Mestre de camp. Soon after, he was made a "Chevalier de St. Louis".