Desc: The Late Queen's Sister: Directed by Micah Smalling-Green. With Vivienne Pettitt, Ingrid Seward, Christopher Warwick. Queen Elizabeth II was the longest-reigning monarch in British history. During her reign, she saw World Wars, presidential assassinations, moon landings, disasters and many other memorable events. The Queen outlived all those dearest to her, watching the world change with their passing. Her reign represented an enormous change for the country - in seventy years, Her Majesty remained the only constant. Throughout Her Majesty's life, she was surrounded by influential people who left their mark in time, including her infamous younger sister, Princess Margaret. Princess Margaret, Countess of Snowdon, was very different from the Queen as she was commonly known as a rebellious royal. But despite their natural differences, Princess Margaret always had a close-knit relationship with the Queen throughout her reign. Follow the story of Princess Margaret, The Late Queen's Sister.