Winston Churchill was not the only Prime Minister to use the Cabinet War Rooms; Neville Chamberlain was the Prime Minister until May 1940, for the first several months of the war. However, Chamberlain's nine-month term as War Leader only allowed him to hold one meeting in the War Rooms.
Churchill spent much time in the Cabinet War Rooms, and although his accomadations were the best in the Rooms, he rarely slept there. From this office, Churchill broadcasted to the world during darkest days of the war, in 1940.
He sometimes entertained guests here, but the curtains might be well pulled in front of the maps that displayed clearly the vital points of Britain's war effort and possible sites of an invasion.
To be able to communicate securely with the leaders of the US, a special telephone was developed that could scramble the conversation, enabling Churchill and Roosevelt to communicate securely. The bulky scrambling equipment was located off site, underneath an Oxford Street department store, where it required a room full of circuit boards and large amounts of energy to send even the briefest of messages.
To disguise its existence, the Transatlantic Telephone Room's door was labeled as a bathroom, leading many in the compound to believe that the only flush toilet on site was located in there, reserved for the Prime Minister.
