From the birth of the house of Windsor in 1917, its leading women - Queen Mary, the Queen Mother, the Duchess of Windsor and Queen Elizabeth II - faced the perils of abdication and assassination, revolution and the rise of fascism, the threat of invasion and all-out war. Their sartorial decisions, alongside those of their royal husbands, projected power and perpetuity, diplomacy and defiance.

In this cinematic story of espionage and exquisite couture, Justine Picardie reveals the undercover lives of the creators behind the façade - including Hardy Amies, Cecil Beaton, Norman Hartnell and Edward Molyneux - and traces the ways in which visual iconography safeguarded the monarchy, even when their reign seemed to be hanging by a thread.

Drawing on original research in the Royal Archives and her own experiences at Balmoral, Windsor Castle and Buckingham Palace, Picardie explores the family feuds and international conflicts that challenged the Crown, and how royal fashion has long been wielded as a weapon.