During the First World War, the British Army and Royal Navy had separate signals intelligence agencies, MI1b and NID25 (initially known as Room 40) respectively. In 1919, the Cabinet's Secret Service Committee, chaired by Lord Curzon, recommended that a peacetime codebreaking agency should be created, a task which was given to the Director of Naval Intelligence, Hugh Sinclair. Sinclair merged staff from NID25 and MI1b into the new organisation, which initially consisted of around 25–30 officers and a similar number of clerical staff. It was titled the "Government Code and Cypher School", a cover-name which was chosen by Victor Forbes of the Foreign Office. Alastair Denniston, who had been a member of NID25, was appointed as its operational head. It was initially under the control of the Admiralty and located in Watergate House, Adelphi, London. Its public function was "to advise as to the security of codes and cyphers used by all Government departments and to assist in their provision", but also had a secret directive to "study the methods of cypher communications used by foreign powers". GC&CS officially formed on 1 November 1919, and produced its first decrypt prior to that date, on 19 October.