Supported by Antoine Crozat and Samuel Bernard, two other former financiers of Louis XIV, the brothers undertook to manage the consequences of the collapse of Law system.

In December 1721, he acquired the lordship of Plaisance (near Nogent) and undertook the reconstruction of the château there, turning it into a residence designed according to his own specifications.

Under the ministry of the Duke of Bourbon, in which he served as principal secretary, he enjoyed the support of the Marquise de Prie and proposed a new tax, the 'cinquantième' (2% levy)[2] as well as a number of measures which provoked the opposition of both the Parlement of Paris and the nobility.

His record in managing the public debt in 1721 and monetary policy from 1724 to 1726 was called into question by Nicolas Dutot in his work 'les Réflexions politiques sur les finances et le commerce' , and he defended himself by dictating, to his former cashier, François Deschamps, a two-volume work entitled 'l' Examen du livre intitulé réflexions politiques sur les finances et le commerce' which he had published at The Hague in 1740.

From 1760 he protected and financed Pierre Beaumarchais, whom he introduced to the business world in exchange for favours at Court and for commercial and financial missions.