HMS Arethusa was the name ship of the Arethusa class of light cruisers. She was laid down at Chatham Dockyard in October 1912, launched on 25 October 1913, and commissioned in August 1914 as flotilla leader for the Harwich Force. On 11 February 1916 she struck a mine off Felixstowe claimed to have been laid by UC-7, drifted ashore before she could be rescued and broke her back.