As Hitler prepared to invade Poland during the sweltering summer of 1939, men and women from across London’s museums, galleries and archives formulated ingenious plans to send the nation’s highest prized objects to safety.

Using stately homes, tube tunnels, slate mines, castles, prisons, stone quarries and even their own homes, a dedicated bunch of unlikely misfits packed up the nation’s greatest treasures and, in a race against time, dispatched them throughout the country on a series of top-secret wartime adventures.

National Treasures highlights a moment from our history when an unlikely coalition of mild- mannered civil servants, social oddballs and metropolitan aesthetes became the front line in the heritage war against Hitler.

Caroline Shenton shares the interwoven lives of ordinary people who kept calm and carried on in the most extraordinary of circumstances in their efforts to save the Nation’s historic identity.