He was minister of foreign affairs under King Louis XV from 1744 to 1747. The son of a lawyer, he received legal training and from 1720 to 1724, served as intendant (royal agent) in Hainaut. As patron of the Club de l´Entresol in Paris, he discussed the political concepts of the Enlightenment with Voltaire and othe Philosophes.
In November 1744, several months after France had officially entered the War of the Austrian Succession (1740-48) on the side of Prussia, Argenson was appointed Louis XV´s foreign minister.
Aspiring to re-establish French hegemony in Europe, he tried unsuccessfully to implement his own doctrinaire schemes for international arbitration. His plans were directed against Spain, Austria, and Russia. Neverthless, his program was undermined by Louis´s own secret diplomacy -about which the minister was not informed- and by court intrigues.
By failing to press the diplomatic advantage that resulted from the victory over the Austrians at Fontenoy (May 1745), he left himself open to scathing criticism. In January 1747 he was compelled to resign. As president of the Académie des Inscriptions et Belles-Lettres, Argenson spent the rest of his life in literary pursuits. His Journal et mémoires (published 1859) forms one of the major sources for the literary and political history of Louis XV´s reign.