The first two ships, "Littorio" and "Vittorio Veneto", were operational by the early months of Italy's participation in World War II. They formed the backbone of the Italian fleet, and conducted several sorties into the Mediterranean to intercept British convoys, though without any notable success. The two ships were repeatedly torpedoed throughout their careers: "Littorio" was hit by a torpedo during the attack on Taranto in November 1940 and again in June 1942; "Vittorio Veneto" was torpedoed during the Battle of Cape Matapan in March 1941 and while escorting a convoy to North Africa in September 1941. "Roma" joined the fleet in June 1942, although all three ships remained inactive in La Spezia until June 1943, when all three were damaged in a series of Allied air attacks on the harbor.