Appointed colonel in 1791, Ferrand was made the commandant of the fortress of Valenciennes the next year. Promoted to maréchal de camp, he led the left wing at the Battle of Jemappes. He was elevated in rank to general of division in May 1793. Ordered by his turncoat superior Charles François Dumouriez to surrender Condé-sur-l'Escaut and Valenciennes, Ferrand refused to carry out his instructions. After the two-month long Siege of Valenciennes, he surrendered the city to Prince Frederick, Duke of York and Albany. Sometime after being paroled, he was imprisoned by the Committee of Public Safety for being from the old nobility. He avoided the guillotine and was released when the government of Maximilien Robespierre was overthrown. Napoleon Bonaparte later named him Prefect of Meuse-Inférieure but he retired in 1804, pleading bad health. His surname is one of the names inscribed under the Arc de Triomphe, on Column 4.