Among the painter's most famous works are portraits of his father, Marcel Proust (private collection, Paris), the poet Pierre Louÿs, the Thaulow family (Musée d'Orsay, Paris), Aubrey Beardsley (National Portrait Gallery, London), and Yvette Guilbert and the infamous beauty Virginia Oldoini, Countess of Castiglione whom his father had treated for mental illness.