[2] Upon the accession of Louis-Philippe d'Orléans to the French throne in 1830, Walewski was dispatched to Poland, later the same year being entrusted by the leaders of the Polish November Uprising of 1830 as a diplomatic envoy to the Court of St James's.

He is said to have collaborated with the elder Dumas on Mademoiselle de Belle-Isle and a comedy of his, L'Ecole du monde, was produced at the Theâtre Français in 1840.

[2] Later that year the prime minister of France Thiers, also a man of letters, became patron to one of Walewski's papers, Le Messager des Chambres, before sending him on a mission to Egypt.

Under Guizot's government Walewski was posted to Buenos Aires to liaise with the British Ambassador, John Cradock, 1st Baron Howden.

The latter treaty did contain an important novelty in international law, creating the possibility for nations that were not involved in the establishment of the agreement, to become a party by acceding to the Declaration afterwards.