Constant Léon Duval (1877–1956) was a French painter, draftsman, and poster artist.A distinguished landscape painter, he participated in various art exhibitions in Paris between 1900 and 1910.From 1910 until 1937 (the year the French railways were nationalized and the SNCF was created), he produced the majority of the railway company’s posters. His talent as a landscape artist, applied to the natural and historic sites accessible by rail, left a lasting impression on station walls and passersby on the platforms.Today, he is one of the most sought-after illustrators in the world of vintage posters.