Antoine Bibesco developed a strong friendship with Marcel Proust that lasted more than twenty years.
From the very beginning, Antoine believed in the talent of Proust and made a concerted effort for his book Swann's Way to be published by André Gide and the Nouvelle Revue de France, but without success. In this book, the character of Robert de Saint Loup is inspired by Bibesco.
Until the very end, Bibesco remained close to Proust. Confined to his room because of his asthma, Bibesco regularly visited the ailing writer to bring news of Parisian society. After his death, their correspondence was published.