The Map Room at the Cabinet War Rooms was staffed day and night throughout the Second World War. It was here that some of the most important strategic decisions of the war were planned. It was in this room that Churchill spent the entirety of D-Day. And only a handful of people even knew this room existed. What exactly went on in the top secret Map Room in the Cabinet War Rooms, who worked here, and why will some of these details will continue to remain a mystery to this day?

What was it like to work here?

On the 16th August 1945, the lights were turned off in this basement room for the first time in 6 years. The staff left in a hurry. This room had been manned day and night throughout the second world war. It was here that some of the most important strategic decisions of the war were planned. It was in this room that Churchill had spent the entirety of D-Day. And only a handful of people even knew this room existed.

We’re going to take a close look at what exactly went on in the top secret Map Room in the Cabinet War Rooms, what it was like to work here, and why some of those details will continue to remain a mystery to this day.

Emma Ellis: "So here we are in the Map Room of Churchill War Rooms and this is one of the most top secret and important rooms of the entire Second World War. Only a handful of people would ever have been allowed to come in here. Of course, Winston Churchill, some key members of the war cabinet and the men working in this room as well. So there were 5 senior men working in this room, they were nicknamed the Glamour Boys because their work was so top secret it was thought to be rather mysterious and glamorous. And there would only be a few of them that would be working in here at any one time, of course on a shift pattern, maybe 12 hours at a time. And they would comprise of three men from the military, so one from each branch of the military, the army, Royal Navy and Royal Air Force. One from the civil service, and then another from any branch of the military who would act as the duty officer."

The committee working in the Map Room were highly esteemed First World War veterans,working alongside nine plotters and two clerks. The information they collated was examined by the Joint Planners and the Joint Intelligence Staff, who used this information to create strategic options, from which the Chiefs of Staff would make crucial decisions that directed the course of the war.

Work began at the Cabinet War Rooms on 27 August 1939. One of the men who worked down here was RAF Officer William Dickson, and he was on already on duty in the Map Room when war was declared.

William Dickson: "I actually, in addition to my planning duties was responsible for the Air Force map keepers in the Prime Minister's Map Room. And there it was on the first day of war. The Prime Minister had  announced we were at war with Germany and we were all down in the map room when the white telephone rang. Plots began to appear on the fighter command operations rooms; enemy raids coming into this country from various directions. And then the most extraordinary thing happened. We had one telephone in the war room which as the Prime Minster's private telephone from 10 Downing Street into this underground operations room. It was the Prime Minister's personal secretary to say the Prime Minster had heard the alarms and was it alright for him to come out. A couple of minutes later when Newel got on the phone to Dowding and, every single one of these raids was non-existent. Something to do with the switching on of the
radar, they'd all got false plots. Everyone expected that either there would be some period before that Hitler would attack this country or it would be a few minutes after the outbreak of war."

Emma Ellis: "So information was constantly flooding in here. It came in via telephone, telegram and letter. And the phones in the middle here were nicknamed the beauty chorus. This was a nod to the West End show girls' colourful costumes because phones at the time were usually just black. So this was a real novelty. And the green and black phones like this one just here were scrambler phones. These would encode the conversations so that enemy spies couldn't listen in. And they were powered by this enormous black box of technology which was required for just three of these phones and it took 20 minutes to warm up, but of course that was the most up to date technology at the time. Any paper correspondence would come in via these tubes. These are air suction or pneumatic tubes, still in use in some places, particularly in America, today.

"The Map Room is located within the Cabinet War Rooms which is a series of rooms beneath the streets of Westminster. And they were used when Britain was being directly hit by bombs, so during the Blitz of 1940-1941 and the V-weapons campaign much later in the war as well."

The site was chosen for the Cabinet War Rooms because of its central location under the streets of Westminster. These basements sit directly beneath a goverment building - the public offices, now the Treasury. Down here there are at least 70 rooms, and over the course of the war the workforce expanded from around 50 to 500 staff.

Gaining access to the War Rooms meant going through a strict set of security checks, and the rooms were guarded by marines. The Map Room required even stricter security restrictions, and only a select group of staff were permitted access.

Emma Ellis: "So I'm standing next to one of the large maps in this room. This is the Royal Naval map. And this one is rather special because it shows the movements of anything travelling by sea. And it has hundreds of thousands if not millions of pin holes in it, where the men are charting the information they are receiving. They would also make little labels to be attached by pins onto the maps to show them what the ships were, and essentially what it would take to sink them as well. So it was a real emotional toll on these men working to take the pins out once they'd learnt that a ship had been sunk. And each pin is not just one ship but an entire convoy, so a group of ships, so you can really get a sense of the traffic that was moving around the world at this time. And this information then would be sent to the King, the Prime Minister and the Chiefs of Staff in a daily report, produced every day before 9am. And this then informed the decisions of the war cabinet.

"Beside the map there is also a telephone that leads directly to the Admiralty so the men were able to update the Admiralty as to what was going on in terms of this Royal Naval map. Churchill actually spent the entirety of D-Day in this very room watching this Royal Naval map. Ideally he'd wanted to go out to the front for D-Day on HMS Belfast, but the King said no, he was not allowed to go out. So of course this was the next best thing for him."

Directly next door to the Map Room was the Map Room Annexe. The large map now on in the Annexe spent much of the war hanging in the main Map Room. It charts in great detail the devastating advance of the German forces in Russia in 1941-1942 and their gradual retreat in the years that followed. It gives us a glimpse of what was on display in the map room at some of the most tense moments of the war.

The other two large maps in the Map Room represent the war in the air and on land. The land map currently shows the Pacific, referencing the switch of focus at the end of the war to the fighting in Japan.

Emma Ellis: "After Victory in Europe was won on the 8th May 1945, most of the workers down here were allowed to leave the war rooms. However the men who worked in the Map Room had to continue coming back here until Victory with Japan. And the last date that they've put in their calendar is the 16 August 1945, which the day after the Japanese surrendered."

Alan Melville: "We all met of course well underground in the basement of Storey's Gate. That was alright, it was well ventilated, it was well lit. I was in the senior chap in charge of the Joint Administrative Planning Staff. I used to write the papers for them. Those papers would then be considered by the strategic people and conclusions were reached. But my time was almost wholly devoted to the Japanese, because there was nothing to be done in Europe any longer, that had been planned. But all the plans against Japan were wide open. Particularly the basic strategy: whether the British forces should join the American in the Pacific moving towards the Philippines, or whether the better strategy was to base ourselves on India and move back via Sumatra. And immense studies were produced and it was all absolutely dead secret, top secret. The existence of the argument was kept totally secret."

Emma Ellis: "So after the end of the war, the documents here that were classified were taken to the Ministry of Defence, because of course this was top secret information. So this was the pins were taken out from the maps, and also many of the paper documents. In our collection at IWM we have boxes and boxes of these pins that would have been used on the maps, and just to my left here we have a little chart that tells us exactly what some of pins might have represented. Of course we now don't necessarily know, because these pins were all taken off the maps at the end of the war, because this was classified information. So it's very difficult to construct a picture of what these maps might have looked like during the war.

"So at this desk just here say Wing Commander Heagerty. And he was clearly very keen to leave when he was finally allowed to do so because in this desk right here he actually left something behind that would have been very precious to him. So we have three sugar cubes that were found some 30, 40 years later by the Imperial War Museum still stashed away in a drawer. And these three sugar cubes would have been Wing Commander Heagerty's sugar ration for one entire week."

Not long after the staff had departed, it was decided that these rooms should be preserved as an historical record, and a lot of the rooms are believed to have been left virtually untouched. IWM has many of Wing Commander Heagerty’s private papers in their Collection. Among these papers is a letter dated from 1956 in which his correspondent describes the war rooms having been reopened in relation to the conflict in the Middle East. He goes on to say that the old map room was left untouched and is still there as a museum. The letter demonstrates the fondness which the staff felt for their work here during the war, as well as their recognition of the map room as a particularly important historical record of this work.

Thanks for watching. Book your ticket for the Churchill War Rooms today to explore the rooms from which the war was directed for yourself. And don't forget to like and subscribe to IWM's YouTube Channel.

Discover more

IWM Churchill War Room Tours
© IWM, Churchill War Rooms
Private Tours

Churchill War Rooms Private Tours

Churchill War Rooms
Dates to suit you

Winston Churchill

Churchill War Rooms

Explore the underground headquarters that between 1939 - 1945 acted as the top-secret nerve centre from where Churchill and his inner circle determined the course of the Second World War.

View of the Map Room at Churchill War Rooms
Permanent Gallery

Cabinet War Rooms: Map Room

Churchill War Rooms