His older brother, Charles César de Fay de La Tour-Maubourg (b.11 February 1757-28 May 1831) married Charlotte, daughter of Charles Pinault, de Thénelles, (d.18 June 1837).
His older brother, Charles César de Fay de La Tour-Maubourg (b.11 February 1757-28 May 1831) was also captured at Rochefort, Belgium, and imprisoned with Lafayette in Olmutz prison until September 1797. He married Charlotte, daughter of Charles Pinault, de Thénelles, (d.18 June 1837).