son of Louis of Noailles, lieutenant general, and member of the French Académie des Sciences. Though he served in the army, his tastes were scientific, and for his eminence as a chemist he was elected to the Académie des Sciences in 1777. He became duc d'Ayen in 1766 on his grandfather's death and duc de Noailles on his father's death in 1793. After emigrating in 1792 to escape the Revolution, he lived in Switzerland until the Restoration in 1814, when he took his seat as a peer of France.