French diplomat.

Studied law at the University of Strasbourg. Secrétaire interprète de la légation de France at Mannheim (1757-63). Secrétaire de légation at Dresden (1763-67). Chargé d’affaires at Ratisbonne (1767-68). Résident and consul général at Dantzig (1768).

Named premier commis des affaires étrangères, Vergennes’ undersecretary in charge of American correspondence (1774), with the title of secrétaire du conseil d’état (1776). Ennobled (1778).

Secretly sent to London under the name of Castel for the first relative openings of the treaty which put an end to the American Revolutionary War (1782). Named conseiller d’état.

Born in Masevaux. Brother of Conrad- Alexandre Gérard, first French minister to the United States.