Guglielmo Marconi (pennant number MN) was launched 27 July 1939[1] and completed on 2 February 1940.

On its first wartime patrol in the Mediterranean Sea, Marconi torpedoed the Royal Navy destroyer HMS Escort on 8 July 1940.

En route Marconi sank the neutral Spanish fishing boat Almirante Jose de Carranza.

The attempted transit to the Atlantic was detected by Royal Navy forces; and Bianchi took refuge in the neutral port of Tangier.

After another unsuccessful patrol, Torelli assisted the three Calvi-class submarines on a rescue mission of 254 sailors from the sunken German auxiliary cruiser Atlantis in December 1941.

After an extensive refit, Torelli was again damaged at sea by aircraft on 16 March 1943 and returned to Bordeaux on 3 April.

[7] Torelli was then selected for conversion to a "transport submarine" in order to exchange rare or irreplaceable trade goods with Japan.

[10] It was found at Kobe when Japan surrendered and scuttled by the United States Navy in Kii Suido.

[11] Alessandro Malaspina (pennant number MP) was launched 18 February 1940[1] and completed on 20 June 1940.

Admiral Karl Dönitz visited Malaspina on 30 September to welcome Regia Marina sailors to the German base.