Faced with the impending blitz during the Second World War, Winston Churchill and his cabinet sought protection in an underground headquarters beneath the Treasury building in London. Though the prime minister much preferred to observe the war from the keener vantage point of the top floor of 10 Downing Street (“to the horror of his staff”), the Cabinet War Rooms played host to more than 100 meetings of Churchill’s war cabinet between 1939 and 1945.

Since 2003, when the restored Churchill War Rooms were reopened to the public, visitors have had the opportunity to tour the site for themselves, yet many continue to wonder how a dank storage basement could have become the prime minister’s base of wartime operations, not to mention what life was really like in this underground bunker. Drawing on a wealth of original material, including new firsthand accounts of the people who lived and worked there, distinguished Churchill biographer Richard Holmes provides the first comprehensive history of the Cabinet War Rooms in his new book Churchill’s Bunker.

For those unlikely to be making a pilgrimage to London in the near future, be sure to view the Imperial War Museum’s excellent virtual tour below, and read up on Churchill’s wartime retreat in Holmes’s excellent new book.