HMS Janus

HMS Janus, named after the Roman god, was a Javelin or J-class destroyer of the Royal Navy. She was ordered from the Swan Hunter & Wigham Richardson Limited at Wallsend-on-Tyne as part of the 1936 Build Programme and laid down on 29 September 1937, launched on 10 November 1938 and commissioned on 5 August 1939.
Off Namsos, Norway, on 30 April 1940 the sloop Bittern was mistaken for a cruiser and was badly damaged by German Junkers Ju 87 dive bombers and had to be sunk by Janus. Janus served in the North Sea until May 1940 and had participated in over 20 convoy duties in that time. From May 1940 Janus began Mediterranean duties with the 14th Destroyer Flotilla in Alexandria. She participated in the Battle of Calabria in July 1940 and the Battle of Cape Matapan in March 1941.

Wikipedia