His memoirs are an important source for Russian history under Empress Elisabeth of Russia.
In 1749, he arrived in Turin with the Marquis de La Chetardie, French ambassador to Charles Emmanuel III, the King of Sardinia.
He undertook secret missions for Louis XV in Spain and Russia.
Then he traveled to England, Holland, Austrian Netherlands, and returned to Paris.
Because of his friendship with Prince Henry of Prussia, in 1773 he was captured in Hamburg and imprisoned in the Bastille.