Forty years on: looking back at Prince Charles and Princess Diana's 1981 wedding

Today would have been the 40th wedding anniversary of Prince Charles and Princess Diana . A little after 11.20am on July 29, 1981, millions of people around the world watched as Lady Diana Spencer , then 20, arrived at London's St Paul's Cathedral to marry Prince Charles , then 32, the heir to the British throne. Of course, we now know their love story was not always a happy one. But less than a year after their wedding, they welcomed their first child, son Prince William on June 21, 1982. Two years later, Prince Harry was born, on September 15, 1984. In 1981, the "wedding of the century", as it was dubbed, gripped the British nation and the world. It is estimated that 750 million people, in 72 countries, watched the ceremony when it was televised; a further 250 million listened to the events unfold on the radio. It wasn't the first royal wedding to be aired on television – that honour was bestowed upon Princess Margaret and Antony Armstrong-Jones 21 years earlier, on May 6, 1960. However, it was an occasion steeped with hope and celebration; at the time The New York Times described it as symbolising "the continuity of the monarchy". The couple eschewed Westminster Abbey, the traditional location of British royal weddings, for St Paul's Cathedral, as it sat more guests and allowed a longer procession through the city. More than 3,500 people made up the wedding congregation, notably Queen Elizabeth II and the Duke of Edinburgh, the groom's parents, and international royalty, including then-kings and queens of Belgian, Sweden and Tonga. Margaret Thatcher, UK prime minister, and Robert Muldoon, prime minister of New Zealand, were two politicians in attendance, while Nancy Reagan, US first lady, represented the country at the wedding. There were also a number of entertainers on the guest list, including Irish actor Spike Milligan and Welsh comedian Harry Secombe. The dress worn by Princess Diana on the day has gone down in wedding history. Designed by David and Elizabeth Emanuel, the gown featured a fitted bodice overlaid with panels of antique Carrickmacross lace, which originally belonged to Queen Mary, Prince Charles’s great-grandmother, and the veil boasts 10,000 mother-of-pearl sequins. At 7.6 metres, the sequin-encrusted train is the longest in British royal history to date. "The dress had to be something that was going to go down in history, but also something that Diana loved," designer Elizabeth Emanuel said in Diana: The Portrait , a 2004 book by Ros Coward. "And we knew it was going to be at St Paul's, so it had to be something that would fill the aisle and be quite dramatic." At the time the ivory silk taffeta gown was was valued at £9,000 ($12,500), which is worth roughly $41,000 today. While the wedding ceremony was certainly steeped in heritage, it also featured some significant breaks from tradition. Princess Diana did not promise to "obey" Prince Charles, as is traditionally said in Christian wedding vows – after the groom promises to "love, cherish, and worship" and the bride to "love, cherish, and obey". The couple omitted the word from their vows, which caused a "sensation" at the time, according to Canadian-American political commentator, David Frum. The couple also made mistakes in their vows. Princess Diana muddled Prince Charles's full name, calling him Philip Charles Arthur George, instead of Charles Philip Arthur George. Prince Charles also got his slightly wrong when he referred to "thy goods", not "my worldly goods". Following their nuptials, the couple went to Buckingham Palace for an "intimate" wedding breakfast with 120 guests. The breakfast was followed by a balcony appearance when the duo greeted the gathered crowd with other members of the royal family. The couple kissed on the balcony, which sparked a tradition of newly wed royal couples kissing for the crowd. On the day there was a staggering total of 27 wedding cakes, but the official cake was made by David Avery, head baker at the Royal Naval cooking school in Chatham, Kent. Standing tall at more than 150 centimetres and weighing more than 100 kilograms, the cake Avery made was a layered fruitcake and took 14 weeks. They created two in case one got damaged. Both the Prince of Wales's coat of arms and the Spencer family's crest were incorporated into the design. On the night of the wedding, there was a fireworks display above London's Hyde Park and 100 beacons of light were shone across the country. Forty years on, we know that their marriage was not to last. The couple separated in 1992, 11 years after their wedding. It was announced on December 9, 1992, by then-prime minister John Major, that the couple were separating “amicably”. They ultimately divorced in 1996, one year before Princess Diana's tragic death on August 31, 1997. In their divorce agreement, Princess Diana was given the right to keep her Kensington Palace apartments and the title, the Princess of Wales. However, she relinquished Her Royal Highness title and a future claim to the British throne. In the years following the wedding, Princess Diana did not speak of the day fondly. She once described feeling as though her younger self was a "lamb to the slaughter" on her wedding day. "I don't think I was happy," she says in audio recorded for her biography, which was later used in documentary, Diana: In Her Own Words . "I never tried to call it off, in the sense of really doing that, but I think [it was] the worst day of my life." In her controversial BBC Panorama interview with Martin Bashir in 1995, she said: "The day I walked down the aisle at St Paul's Cathedral, I felt that my personality was taken away from me, and I was taken over by the royal machine."

Forty years on: looking back at Prince Charles and Princess Diana's 1981 wedding

Princess Diana may have described herself as a 'lamb to the slaughter' in the years after her wedding to Prince Charles - but what happened at the 'wedding of the century', back in the early 1980s?