With the eyes of 750 million people around the world upon her, the former kindergarten teacher with the schoolgirl looks was playing out a fairy tale, the dazzling quality of which had never been seen before this century. Not since the Queen's coronation had a royal event so touched the hearts of the nation.
Everything seemed magical on that summer day in 1981: the new Princess of Wales was pretty, innocent, unassuming, and young - the perfect match for the charming and gentle 32-year-old heir to the throne.
But 11 years later, the country has forgotten the wedding and that public kiss on the balcony of Buckingham Palace. All that remains is the sad and often bitter story of a man and a woman who should never have been married, and who seem to have come to that conclusion themselves a long time ago.
The Prince of Wales was two years older than the age he had publicly declared to be the most suitable one for marriage. He was also acutely aware of his public responsibility. 'Marriage is a much more important business than falling in love,' he had said before his marriage. 'Essentially you must be good friends, and love, I'm sure, will grow out of that friendship. I have a particular responsibility to ensure that I make the right decision. The last thing I could possibly entertain is getting divorced.'
His proposal on 3 February 1981 was a relatively hasty affair: although he first met his future wife in November 1977, he had only started taking a real interest in her the previous summer.
He started courting her, throwing her into a state of adoring confusion, and asked her to marry him after returning from a skiing holiday. His proposal in the nursery at Windsor Castle was greeted apparently by a girlish attack of the giggles. Recovering, Lady Diana poured out her love for him, and then returned to tell her flatmates what had happened. 'Guess what?' she is reported to have said after collapsing on her bed. 'He asked you,' cried her friends. 'He did and I said 'Yes please',' she said.
But the euphoria was shortlived. Even before her marriage, she is said to have been suffering from the eating complaint bulimia nervosa, a condition which worsened as the marriage wore on. She was also distressed about the Prince's continuing friendship with Camilla Parker-Bowles.
Despite the early photocall on the Balmoral estate, where the couple seemed in photographs to be blissfully in love - the Princess of Wales said she could 'highly recommend' marriage - it was not long before the cracks started to emerge.
As early as January 1982, the Princess is reported as having made the first of several suicide attempts. Three months pregnant with Prince William, she threw herself downstairs at Sandringham after her husband had ignored a cry for help.
Early on, however, there had been some affinity between the two. When Prince William was born, his father initially took an interest in his new role.
But he was soon disagreeing with his wife over the upbringing of the family. He wanted the children to be brought up by his former nanny, and he also thought they should be educated initially by a governess at Kensington Palace. The Princess wanted the children to go to school in the normal way, and to be spared the rather spartan upbringing her husband had endured.
The Prince of Wales gave in, and had little more to do with family decisions: it was the beginning of the end of the marriage.
By the time Prince Harry was born in September 1984, the Prince of Wales's enthusiasm for family life appeared to have dimmed. He is reported to have wanted a girl, and to have said at the birth: 'Oh it's a boy, and he's even got rusty hair.'
In September 1987, the press homed in on the couple's separate lives after the Prince flew to Balmoral, leaving his family behind at Kensington Palace. The couple did not see each other for a month, and when they did come together at a public engagement in Wales, the Prince ignored his wife. Their isolation from each other was plain.
This was accentuated in June last year, when the Prince visited Prince William in hospital after his son was involved in an accident at school. He left to go to the opera amid criticism over his apparent lack of concern.
Later, the Princess of Wales reportedly expressed surprise when a newspaper alleged that the Prince had ignored her at a concert to celebrate the Queen Mother's 90th birthday. 'He ignores me everywhere and has done for a long time. He just dismisses me,' she said.
Two months after the publication of Andrew Morton's book Diana: Her True Story, the 'Dianagate' story broke: it gave details of an intimate telephone conversation between the Princess and a man believed to be an old friend, James Gilbey.
Last month, the Waleses visited South Korea but no reconciliation was in sight. So yesterday, the couple acknowledged that the fairy tale had come to a close. The real question is this: did it ever even begin?