With the development of anti-submarine equipment as depth charges, howitzers and hydrophones during World War I, HMS Osprey was born from the increasing need for anti-submarine training and research. The establishment at Portland was commissioned as an independent shore command and parent ship of the First Anti-Submarine Flotilla on 1 April 1924. It was responsible for training personnel in the use of anti-submarine equipment and the development of experimental equipment, including ASDIC and later sonar. HMS Osprey moved ashore in 1927 as a shore-based establishment. Following a major rebuild, King Edward VIII made an official visit to view the establishment in 1936. Due to HM Naval Base Portland being a prime target of the Luftwaffe during World War II, Osprey was transferred to Dunoon in Scotland in 1940, leaving Portland's shore-base to become HMS Attack. HMS Osprey returned to Portland in 1946 and the experimental section evolved into HM Underwater Detection Establishment in 1947. In 1959-60, HMUDE merged with Portland's Admiralty Gunnery Establishment to become the Admiralty Underwater Weapons Establishment. Owing to the highly-classified work carried out there during the Cold War, the AUWE became the centre of worldwide attention in 1961 after the discovery of espionage infiltration. This became infamously known as the Portland Spy Ring, a Soviet spy ring that operated in England from the 1950s till 1961 when the core of the network were arrested by the British security services. 1959 also saw the commissioning of RNAS Portland, which was responsible for developing helicopters in an anti-submarine role, including the training of crews. From 1968, HMS Osprey was one of the designated locations for plan PYTHON, the plan for continuity of government in the event of nuclear war. The end of the Cold War and subsequent defence budget cuts resulted in the closure of HM Naval Base Portland in 1995, as well as the AUWE research establishments, by then operated by the Defence Evaluation and Research Agency. RNAS Portland's closure followed on 31 March 1999. The former air station site has now been redeveloped as an industrial and recreational site, Osprey Quay, while the HMS Osprey complex at East Weares was demolished in 2004-05 by Portland Port Ltd, the new owners and operators of the harbour.
