The Arethusa-class was the name class of eight oil-fired light cruisers of the Royal Navy all ordered in September 1912, primarily for service in the North Sea. They had three funnels with the middle one somewhat larger in diameter than the others. HMS Arethusa herself was laid down at HM Dockyard Chatham in October 1912, launched on 25 October 1913, and commissioned in August 1914. She became flotilla leader for the Harwich Force. This consisted of between four and eight light cruisers, several flotilla leaders and usually between 30 and 40 destroyers, with numbers fluctuating throughout the war, and organised into flotillas. On 28 August 1914 she fought at the Battle of Heligoland Bight. She was seriously damaged by the German cruisers SMS Frauenlob and SMS Stettin and was towed home. In December she took part in the Cuxhaven Raid and on 24 January 1915 she fought at the Battle of Dogger Bank. She was transferred to the 5th Light Cruiser Squadron of the Harwich Force and in September she captured four German trawlers. On 11 February 1916 she struck a mine off Felixstowe, drifted onto a shoal while under tow, and broke her back.