Background: From 1946 to 1964 five Departments of State did the work of the modern Ministry of Defence: the Admiralty, the War Office, the Air Ministry, the Ministry of Aviation, and an earlier form of the Ministry of Defence. These departments merged in 1964; the defence functions of the Ministry of Aviation Supply merged into the Ministry of Defence in 1971.
Question: During what years did the five Departments of State do the work of the modern Ministry of Defence?
Answer:<extra_id_0>.
<extra_id_0> 1946 to 1964<extra_id_1>