The Surcouf (N N 3) was ordered in December 1927, launched 18 October 1929, and commissioned in May 1934. Surcouf, named after the French privateer Robert Surcouf, was the largest submarine ever built, until being surpassed by the Japanese I-400. Her short wartime career was marked with controversy and conspiracy theories. She was classified as an "undersea cruiser" by sources of her time and carried two 8" (203mm) guns in a twin turret as well as anti aircraft weapons and torpedoes.