[2] De Faÿ was charged, with Antoine Barnave and Jerome Pétion, with returning the royal family to Paris following its flight to Varennes in June 1791.

However, in her memoirs, Madame Tourzel, witness to the facts, paid tribute to his dedication to the royal family.

With the separation of the National Constituent Assembly, he accompanied the marquis de Fayette with the Army of the Center in 1792 and emigrated with him after the dismissal by Louis XVI on 10 August 1792.

Captured at Rochefort, Belgium, with Lafayette, and imprisoned by Austria, he was released after the Treaty of Campo-Formio (18 October 1797) and lived in exile in Hamburg.

Concerned with the management of its inheritance, he took part in financing the industrial activities of Pierre Samuel du Pont de Nemours, scion of the American business family.

In 1814, de Faÿ was named at the time of the Bourbon Restoration and preserved his position during the Hundred Days.

The second, Jenny, married General Ettore Perrone di San Martino, politician of the Kingdom of Piedmont-Sardinia.

A portrait of his wife painted by Théodore Chassériau was recently acquired by the Metropolitan Museum in New York.

[14] After the death of her husband, the marchioness withdrew to her various residences at Maubourg, Paris, Cannes and Glareins (Ain).

The last descendants of the Faÿ family de la Tour-Maubourg are buried in a mausoleum in the commune of Saint-Maurice-de-Lignon, built from the plans of Lyons architect Carra.