Military man. Governor of Condé (1776). Inspecteur des grenadiers royaux de Picardie (1781). Maréchal de France (1783).

Led a distinguished military career. Attempted to perfect the defense of coastal towns. Constructed the Tour de Croy near Boulogne. Restored the port of Dunkerque.

Friend of various scientists and philosophers. Interested in natural history, botany, astronomy, and voyages of discovery.

Wrote several memoirs on military and other subjects including Les meilleures limites de la France (1775) for the comte de Vergennes, and Mémoire pour étendre la langue française aux Etats-Unis (1782) for Franklin.

Born in Condé, Hainaut. Married in 1746 to Angélique-Adélaïde d’Harcourt.