A lip reader has revealed the very important reminder the Queen gave to Diana on her wedding day.
Charles proposed in the nursery at Windsor Castle on 3 February 1981, only six months after he started dating Diana.
Their engagement became known publicly when the couple announced their impending nuptials on 24 February 1981 and Britain eagerly held its breath for the upcoming wedding.
They were engaged for five months before they tied the knot in July of that year in a spectacular ceremony broadcast on screens across the nation.
Charles and Diana married at St Paul's Cathedral in London and they selected the cathedral over the traditional venue for royal weddings, Westminster Abbey, because it would hold more people - 3,500 guests.
MailOnline can reveal the future King said 'you look perfect' then told Diana to 'give me your hand', which she does, and he then said to her 'kissy'.
When the future King saw his bride, he was met by chants of 'give her a kiss'
Queen Elizabeth pointed to the crowd while whispering to the princess to tell her to 'look' at the people who have 'been there all day' to see her
A lip reader has revealed an important reminder the Queen gave to Diana on her wedding day
MailOnline can now reveal he said 'you look perfect' then told her to 'give me your hand', which she does, and he then said to her 'kissy'.
But after other members of the Royal Family joined them on the balcony the then-Prince of Wales commented: 'It's an awful long time. We need to eat.'
Queen Elizabeth pointed to the crowd while whispering to the princess to tell her to 'look' at the people who have 'been there all day' to see her.
When the future King saw his bride, he was met by chants of 'give her a kiss', which he complied with.
Sources said that despite her shyness, Diana loved the glamour that marrying a prince would offer, and there were 'some tears' and champagne when she made the announcement.
But Penny Thornton, who served as Princess Di's royal astrologer, said Prince Charles left Diana 'devastated' when he told her he didn't love her the night before their wedding
Charles so deeply questioned his decision to marry Diana that he considered calling off the wedding altogether, royal reporter Robert Jobson revealed in a tell-all biography published in 2018.
He felt the pair were 'incompatible' but felt that the impending nuptials were out of his control, and believed that ending the engagement would have been 'cataclysmic.'
However, the Queen's former press secretary said that despite Charles's doubts, the pair were truly in love - and couldn't keep their hands off each other as newlyweds.
According to Dickie Arbiter, there was a 'genuine relationship' from the start, with 'genuine love and happiness' there.
They were engaged for five months before they tied the knot
Sources said despite her shyness, Diana loved the glamour that marrying a prince would offer
After they divorced, in April 2005, the Prince of Wales married Camilla Parker Bowles
In tapes released after her death, Diana noted that the 'Camilla thing' had cast a shadow over the day.
'I was desperately trying to be mature about the situation, but I didn't have the foundations to do it, and I couldn't talk to anyone about it.'
The princess also revealed that she had a 'very bad fit' of bulimia the night before, eating everything in sight, only to be 'sick as a parrot' later.
In addition to the bride and groom's families, Margaret Thatcher, the then Prime Minister of the UK, attended the wedding of Charles and Diana.
Other guests who were in attendance included Nancy Reagan, French president Francois Mitterrand and a host of royal dignitaries from around the world. Camilla Parker Bowles was also in attendance.
The event that became known as 'The wedding of the century' was broadcast on TVs around the world. An astonishing 750 million people across 74 countries tuned in to watch Charles and Diana get married.
Charles and Diana's vows broke with tradition when Diana omitted the promise 'to obey' her husband. She was the first royal to ever do so, but not the last: Kate Middleton also dropped the phrase when she married Prince William in 2011, as did Meghan Markle when she married Harry in 2018.
The event that became known as 'The wedding of the century' was on TVs around the world
In April 2005, the Prince of Wales married Camilla Parker Bowles. The Queen and Prince Philip - mother and father of the groom - were nowhere to be seen
Both Charles and Diana flubbed their vows. Diana called her new husband 'Philip Charles' instead of 'Charles Philip' and Charles got the phrase 'All my worldly goods with thee I share' completely wrong, saying instead: 'All thy goods with thee I share.'
In December 1992, the then Prime Minister John Major announced that the Prince and Princess of Wales had decided to separate.
In a TV documentary made the following year by Jonathan Dimbleby, the prince confessed to his own adultery.
Diana's own riposte to Charles came on November 20, 1995, when over 23 million British viewers watched the princess nervously but deftly answer the questions of Martin Bashir, a young reporter on Panorama.
'There were three of us in this marriage,' was her edgy skewering of the Camilla situation.
The dream marriage formally came to an end in August 1995.
But just one year and three days later, the British ambassador in Paris rang Balmoral around 1am, rousing the duty private secretary, Robert Janvrin, from his sleep. The embassy was receiving police reports, he said, of a serious car crash that involved the Princess of Wales.
The news of Diana's death came through from Paris just before 4am.
And in April 2005, the Prince of Wales married Camilla Parker Bowles.
The Queen and Prince Philip - mother and father of the groom - were nowhere to be seen when the civil ceremony took place.
Later, though, Queen Elizabeth grew fond of Camilla, so much so that in 2022 the late Monarch publicly announced that she would like her daughter-in-law to become Queen Consort when Charles took over the throne.