This is the compelling, true story of Princess Margaret - a force of modernity who helped reshape our image of the monarchy. What do you do when your sister is the Queen? Princess Margaret became the royal rebel who re-defined ideas of how a princess might live in the modern world. Her life spanned a period of social change and a sexual revolution that would transform society. Blazing a trail through scandals, romances and heartbreak, this royal pioneer paved the way for those who followed - from Diana, Princess of Wales to Meghan, Duchess of Sussex.