After Italy entered World War II in June 1940, "Trento" and "Trieste" saw extensive action against British forces in the Mediterranean Sea, including at the battles of Calabria, Cape Spartivento, and Cape Matapan in July and November 1940 and March 1941, respectively. In November 1941, "Trieste" was torpedoed by the submarine ; she spent most of the next year under repair. In the meantime, "Trento" was also present during the inconclusive First and Second Battles of Sirte. The Italian fleet sortied to attack the British Operation Harpoon convoy in June 1942, and while on the way, "Trento" was torpedoed twice, first by a Bristol Beaufighter torpedo bomber and then sunk by the submarine with very heavy loss of life on 15 June. "Trieste" was moved to La Maddalena, Sardinia, where she was later sunk by United States heavy bombers on 10 April 1943.