Superintendent of Louis xvi’s buildings and gardens.

Cavalry page (1744). Gentleman-in- waiting to the Dauphin’s children; friend and mentor of the future Louis xvi. Chevalier de Saint-Louis (1756). Superintendent of royal buildings and gardens (1774). Prominent patron of the arts. Narrowly escaped arrest during the Revolution (1791); fled to Russia under an assumed name. Remained an adamant monarchist and refused to return to France.

Son of Charles-César and Thérèse (de Coeur) de La Billarderie. Married the baronne de Marchais, his long-time mistress (1781); they were later divorced.