François XIII, duke of La Rochefoucauld' was the heir and eldest son of François Alexandre Frédéric, duc de la Rochefoucauld-Liancourt. On 24 September 1793 he married Marie-Françoise de Tott at La Haye. Their daughter, Fanny, was one of the mistresses of Anatole Demidov, and bore him an illegitimate child.