All seven ships saw extensive service in the Mediterranean Sea during World War II, where they repeatedly engaged elements of the British Royal Navy. Italian heavy cruisers took part in the Battles of Calabria, Taranto, Cape Spartivento, Cape Matapan, First and Second Sirte between 1940 and 1943. Three of the "Zara"s—, , and "Pola"—were sunk in a close-range night action with British battleships at the Battle of Cape Matapan in 1941, "Trento" was torpedoed and sunk by British forces in June 1942, and "Bolzano" was badly damaged by a British submarine in August 1942, which left her out of action for the rest of the war. United States heavy bombers raided La Maddalena in April 1943, sinking "Trieste" and badly damaging "Gorizia"; the latter vessel and "Bolzano" were later attacked by Italian commandos while Italy was under German occupation in 1944 to prevent the Germans from repairing and reactivating them. They were both raised and scrapped after the war.