At the outbreak of WW2, the British monarchy was in a state of turmoil. The previous king, Edward VIII, had abdicated the throne, leaving his unprepared and terrified brother Bertie to become George VI. Meanwhile, as the now-Duke of Windsor awaited the decree that would allow him to marry his mistress Wallis Simpson, he took an increasing interest in the expansionist plans of the Führer of Germany.

The Windsors at War tells the story of the turbulent and seismic decade in between 1937 and 1947, including the bombing of Buckingham Palace in May 1940, the Duke of Windsor's ill-advised visit to Germany in October 1937 and the death of the Duke of Kent in a plane crash in August 1942. It answers a simple question: how did this squabbling, dysfunctional family manage to put their differences aside and unite to help win the greatest conflict of their lifetimes?