HMAS Sydney was a Chatham-class light cruiser of the Royal Australian Navy (RAN). Laid down in 1911 and launched in 1912, the cruiser was commissioned into the RAN in 1913.
During the early stages of World War I, Sydney was involved in supporting the Australian Naval and Military Expeditionary Force, and escorting the first ANZAC convoy. On 9 November 1914, she defeated the German cruiser SMS Emden at the Battle of Cocos. During 1915 and 1916, Sydney operated on the North America and West Indies Station, before joining the 2nd Light Cruiser Squadron at Greenock, Scotland in November 1916. On 4 May 1917, the cruiser was involved in an inconclusive action against the German zeppelin L43; neither was damaged. During late 1917, Sydney became the first Australian warship to launch an aircraft, and the first warship to do so from a rotatable platform.
After the war’s end, Sydney spent a year in reserve before being reactivated to serve as Flagship of the RAN. The cruiser was decommissioned in 1928 and broken up for scrap. Several sections of the ship, including her bow and foremast, have been preserved as monuments, and three of the ship’s main guns saw later use in shore fortifications.