Born in Paris, he bore the title of Duc de Lauzun, which had passed, on the death of Antoine Nompar de Caumont, duc de Lauzun (1633–1723), to his niece, the wife of Charles Armand de Gontaut, duc de Biron (1663–1756). In 1788, he succeeded to the duchy of Biron on the death of his uncle, Louis Antoine de Gontaut, duc de Biron (1700–1788)