In 1936, the monarchy faced the greatest threats to its survival in the modern era - the crisis of abdication and the menace of Nazism. The fate of the country rested in the hands of George V's sorely unequipped sons: Edward VIII abandoned his throne to marry divorced American socialite Wallis Simpson; Prince Henry preferred the sporting life of a country squire; the glamorous and hedonistic Prince George, Duke of Kent, was considered a wild card; and stammering George VI felt himself woefully unprepared for the demanding role of King.

As Hitler's Third Reich tore up the boundaries of Europe and Britain braced itself for war, the new king struggled to manage internal divisions within the royal family. Drawing on many new sources including from the Royal Archives, Princes at War goes behind the palace doors to tell the thrilling drama of Britain at war.