Marcel Besson was designing aircraft before 1912. After 1914 he produced biplane and triplane trainers, followed in 1917 by triplane flying-boats powered by pusher engines of 180, 300 or 450 hp. Called LB, from being built by Hydravions Georges Levallois et Levy, they were made in small numbers. H.3-H.6 were flying-boats of 1920-21. Besson then built his own prototypes, calling them MB, best known being MB.26 fighter and reconnaissance seaplanes of 1925 and light MB.35 seaplane of 1926. Besson's lack of funds resulted in his becoming a division of ANF Les Mureaux, enabling him to finish big MB.36 transport flying-boat by 1930. Last design, MB.411 observation seaplane, escaped to Britain aboard parent submarine Surcouf 1940.