On 2 August 1939, war with Germany was imminent. Vulnerable in central London, GC&CS prepared to evacuate to its wartime home, Bletchley Park.
Detailed orders issued to staff asked them to pack their papers in small, lockable cupboards by 17:30 on 14 August. These would be transferred to Bletchley Park overnight. Staff themselves had to arrive on site at Bletchley Park by 10:00 on 15 August. Any curious locals would be told that activities at Bletchley Park were related to the aerial defence of London. The Mansion and the first Huts were ready and waiting, but the growing organisation quickly required more working accommodation. New Huts were planned and built during August 1939, and growth continued as the war began.