For the Bibescos life after the war was more cosmopolitan than Romanian. Among her literary friends and acquaintances, Marthe counted Jean Cocteau, Paul Valéry, Rainer Maria Rilke, François Mauriac, Max Jacob, and Francis Jammes. In 1919, Marthe was invited to Prince Antoine Bibesco's wedding in London to Elizabeth Asquith, daughter of the former Prime Minister of the United Kingdom, H. H. Asquith, later Earl of Oxford and Asquith. Princess Elizabeth Bibesco, who died in Romania during World War II, is buried in the Bibesco family vault on the grounds of Mogoșoaia. Marthe for many years occupied an apartment in Prince Antoine's Quai Bourbon house at which she held literary and political salons.