The late princess died in August in the late 1990s in an accident in France, leaving behind
her two sons.
Prince William, now aged 39, was 15 at the time and Prince Harry, age 36, was just 12 at the time.
So when did Diana marry Prince Charles when did she die, and what were the circumstances of her untimely death?
When did Diana die - and what happend?
Princess Diana was 36 when she died in a car crash in Paris on August 31 1997.
The crash happened in the Pont de l'Alma tunnel in Paris while the driver was fleeing the paparazzi who were pursuing the princess.
The crash also resulted in the deaths of her companion Dodi Fayed and the driver, Henri Paul, who was the acting security manager of the Hôtel Ritz Paris.
Diana's bodyguard, Trevor Rees-Jones, survived the crash.
What was the public reaction to Diana’s death?
There was a huge outpouring of grief from the public after the shocking and unexpected death of Princess Diana, who had been taken into the hearts of the nation as the people’s princess.
People left public offerings of flowers, candles, cards, and personal messages which were piled high outside Kensington Palace for many months following her passing.
Diana’s funeral, which took place at Westminster Abbey, on 6 September 1997, was televised and watched by a British television audience that peaked at 32.10 million - one of the United Kingdom's highest viewing figures ever.
Millions more people also watched the event around the world.
When was Diana’s funeral?
Diana’s funeral took place in Westminster Abbey on 6 September.
Her sons walked in the funeral procession behind her coffin, along with her ex-husband Prince Charles, the Duke of Edinburgh, Diana's brother Lord Spencer, and representatives of some of her charities.
Lord Spencer said of his sister at the time: "She proved in the last year that she needed no royal title to continue to generate her particular brand of magic.”
Elton John performed ‘Candle in the Wind 1997’, which had been re-written in tribute to Diana.
This is the only occasion the song has been performed live. Released as a single in 1997, the global proceeds from the song have gone to Diana's charities.
When did Diana marry Prince Charles?
Princess Diana was the first wife of Prince Charles, the heir to the throne.
Together, they had two children - Prince William and Prince Harry - but they divorced after 15 years of marriage.
They got married in 1981 and divorced in the year before Diana’s death, in 1996.
Diana famously told BBC’s Panorama in 1995 that “there were three of us in this marriage, so it was a bit crowded,” referring to Charles’ affair with Camilla.
Charles and Camilla got married in April 2005.
A report has since condemned former BBC journalist Martin Bashir’s unethical behaviour during that interview.
What conspiracy theories have there been surrounding her death?
The initial French judicial investigation into the accident at the time concluded that the crash was caused by Henri Paul’s reckless driving, speeding, and effects of prescription drugs.
In February 1998 Mohamed Al-Fayed, the father of Dodi Fayed, publicly said the crash, which killed Diana and his son, had been planned and accused MI6 and the now late Duke of Edinburgh.
An inquest that started in London in 2004 and concluded in 2008 attributed the crash to grossly negligent driving by Henri Paul and to the pursuing paparazzi, who forced him to speed into the tunnel.
On April 7 2008, the jury returned a verdict of ‘unlawful killing’.
On the day after the final verdict of the inquest, Al-Fayed announced that he would end his 10 year campaign to establish that the accident was a murder in his opinion, saying that he was doing so for the sake of Diana's children, Prince William and Harry.