However he was appointed Secretary of Legation at Genoa, then undersecretary for foreign affairs, before being chargé d'affaires to the Russian court, where he remained until the signing of the armistice of Cherasco between Sardinia and France, on 28 April 1796, when the Tsar Paul I ordered him to leave Russia.
When he learned of the Piedmont states sale that had been made to France, he went to Turin and determined the heads of the Italian party for the meeting.
In order to recognize this welcome, Bossi signaled his entry into the government by an act which gave the Vaudois full freedom of worship.
Made a baron of the Empire by Napoléon 9 March 1809, Louis XVIII kept him in office at the Bourbon Restoration and granted him letters of naturalization, but his eagerness to recognize Bonaparte on his return from Elba, led to his dismissal.
Widowed, she remarried with Caesar-Maurice de la Tour d'Auvergne, and had the Carmel of the Pater Noster built in Jerusalem.