Prior to the
Second World War defence policy was co-ordinated by the
Committee of Imperial Defence (CID). In 1936, the post of
Minister for Co-ordination of Defence was established, though he did not have a department and the political heads of the three services—the
First Lord of the Admiralty for the
Royal Navy, the
Secretary of State for War for the
Army and the
Secretary of State for Air for the
Royal Air Force—continued to attend
Cabinet. On the outbreak of war in 1939, the CID was suspended and on, 3 April 1940, the office of Minister for Co-ordination of Defence was abolished. When
Winston Churchill became Prime Minister in May 1940, he personally assumed responsibility for inter-service co-ordination, with the title of
Minister of Defence, and the heads of the three services were not included in the
War Cabinet. The Minister had few departments, the most famous of which was
MD1 which allowed unusual ideas for weapons to be developed under the patronage of Churchill with less interference from the services and got the nickname "Churchill's Toyshop". After
the end of the war in Europe in May 1945, the First Lord and the Secretaries for War and Air rejoined the Cabinet, though the Prime Minister remained Minister of Defence. The suspension of the CID was made permanent by a
White Paper (Cmd. 6923) in 1946, and, from 4 October that year, the service chiefs were no longer in the Cabinet. and the Ministry of Defence was formally established on 1 January 1947 by the
Ministry of Defence Act 1946. The Ministry was responsible for liaising between the individual service ministries and co-ordinating defence policy. Under the
Defence (Transfer of Functions) Act 1964, the Ministry of Defence was merged with the
Admiralty, the
War Office and the
Air Ministry to form the current
Ministry of Defence on 1 April 1964; the Minister of Defence became
Secretary of State for Defence. ==List of ministers of defence, 1940–1964==