Princess Margaret was very close to her sister, Queen Elizabeth, and her death in 2002 was indeed a devastating loss for Her Majesty.

In the documentary Elizabeth: Our Queen, royal biographer Hugo Vickers said that Margaret had such a significant presence in her older sister's life. She was Queen Elizabeth's confidante and companion since childhood. They talked practically every day and were devoted to each other, especially after the death of their father, King George VI.

Margaret and Elizabeth grew closer when they were adults. As the younger sister, Margaret was dubbed the mischievous royal rebel who had many disagreements with the Queen yet her death left Her Majesty heartbroken.

According to People, Margaret died at the King Edward VII Hospital following a series of strokes. She was already in a state of poor health months before her passing, as she suffered from partial paralysis and had problems with her eyesight.

Upon her death, which took place three days after their father's death anniversary, the Queen released a statement to confirm that her only sister passed away in her sleep. She is survived by her children, David Linley and Sarah Chato.

Margaret was a heavy smoker for most of her life and she loved to party and drink. Biographer Anne Glenconner, who served the royal family for 30 years, wrote in the book, Lady in Waiting: My Extraordinary Life in the Shadow of the Crown, that Margaret was never out of cigarettes or cocktails but she knew she had to give it up when her health weakened.

Glenconner shared what Margaret told her about having no withdrawals from her vices because the royal sister was a practical thinker. Once she made up her mind about anything, Margaret was determined to see her choices through.

Apart from her penchant for cigarettes and drinks, Margaret had such a controversial love life. She was first engaged to a married man and fought with the Queen when she was denied a wedding to her great love, Peter Townsend. Margaret then married Antony Armstrong-Jones, the Earl of Snowdon. But after two decades of marriage, their divorce was finalized in the late 1970s.

By the 1980s, following a series of non-serious love affairs, as well as her lung operation, Margaret decided to devote her time to her sister. Her final public appearance was in 2001 during the 100th birthday of the Queen Mother.

Six weeks after Margaret died, their mother also passed away in her sleep at the Royal Lodge in Windsor.