Enrico Tazzoli was one of three Calvi-class submarines built for the Regia Marina during the 1930s. Completed in 1936, she played a minor role in the Spanish Civil War of 1936–1939 supporting the Spanish Nationalists. She operated in the Atlantic during the Second World War and was second only to the submarine Leonardo da Vinci as the highest scoring Italian submarine of the conflict. Enrico Tazzoli was converted in 1943 to be a submarine transport for blockade-running between Europe and the Far East. She was lost on her first voyage in this role.

BETASOM was a submarine base established at Bordeaux, France by the Regia Marina Italiana during World War II. From this base, Italian submarines participated in the Battle of the Atlantic from 1940 to 1943 as part of the Axis anti-shipping campaign against the Allies.