The Sentinel-class cruiser was a pair of scout cruisers built for the Royal Navy in the first decade of the 20th century. The sister ships spent about half of the first decade of their careers in reserve and were based in home waters when on active duty. When the First World War began in August 1914 they were given coastal defence missions on the north eastern coast of Britain. The ships were transferred to the Mediterranean in 1915 and then to the Aegean in mid-1916 where they remained until the end of the war in late 1918. Skirmisher was paid off in 1919 and was scrapped the following year, but Sentinel supported the British attempt to intervene in the Russian Civil War for a few months after the end of the war. She also returned home in 1919, but served as a training ship for a few year