The RAN became the first of the Australian services to see action in the Mediterranean theatre. At the time Italy entered the war on 10 June 1940 the RAN had a single cruiser () and the five elderly destroyers of the so-called 'Scrap Iron Flotilla' at Alexandria with the British Mediterranean Fleet. During the first days of the Battle of the Mediterranean, "Sydney" sank an Italian destroyer and a submarine. The Mediterranean Fleet maintained a high operational tempo, and on 19 July, "Sydney", with a British destroyer squadron in company, engaged the fast Italian light cruisers and in the Battle of Cape Spada. In the running battle which followed, "Bartolomeo Colleoni" was sunk. The Australian ships spent much of their time at sea throughout 1940. "Sydney"s sister ship, , relieved her in February 1941.