1. The Ceremony
Whilst from the outset the wedding looked like it ran like clockwork there were a few hiccups.
One of the bridesmaids, Clementine Hambro, great-granddaughter of Winston Churchill and one of Diana's former students, tripped, fell and started crying.
Diana herself was soon to the rescue bending down to ask if she'd 'bumped her bottom' which bought a smile to the young child's face.
Both bride and groom fluffed their lines during the ceremony with Diana getting the groom's name wrong. Diana accidentally mixed up his two first names calling him "Philip Charles" Arthur George, instead of 'Charles Philip' Arthur George.
Charles also flubbed his lines too; instead of offering Diana 'my worldly goods,' he said the slightly less enthusiastic, 'thy goods'.
2. The Guests
As befitting a royal wedding, the guest list was heavily weighted with dignitaries from across the globe, all of the Queen's Governors-Generals (including Australia's Sir Zelman Cowen) and most of Europe's most prominent monarchs with the exception of King Juan Carlos I of Spain who decided not to attend due to Spain and the UK's dispute over ownership of Gibraltar.
Most of Europe's heads of state attended along with then First Lady, Nancy Reagan who represented the United States. Charles invited some of his favourite entertainers including Spike Milligan and Harry Secombe.
Not all the attendees were powerful dignitaries; Diana invited the staff of the nursery school where she had worked. One guest who Diana was looking out for was Charles' former girlfriend (and eventually his second wife) Camilla Parker Bowles. Diana said later in a frank interview with royal biographer Andrew Morton in 1991.
'I knew she was in there, of course. I looked for her,' said Diana.
'So walking down the aisle, I spotted Camilla, pale gray, veiled pillbox hat, saw it all, her son Tom standing on a chair. To this day you know — vivid memory.'
3. The Tiara
The Queen had loaned Diana her famous 'Lover's Knot' tiara for the big day but Diana instead opted to wear a family heirloom known as the 'Spencer Tiara'.
Studded with diamonds shaped into tulips and stars, the Spencer Tiara was constructed from various family heirlooms into the famous sparkler sometime in the 1930s. Unfortunately for Diana, the tiara was so heavy that it gave her a terrible headache for the entire day.
Diana's brother, Charles later told the press, 'She had a cracking headache too, because she wasn't used to wearing a tiara all morning.' The tiara has never been worn since Diana's tragic death in 1997.
4. The Dress
Valued in 1981 at an astonishing GBP £151,000, Diana's wedding dress was made of ivory silk taffeta and antique lace gown, with a 25-foot (7.62-metre) train and a 153-yard (140-metre) tulle veil.
Regarded as probably the most iconic wedding dress in history, the gown was designed by David and Elizabeth Emanuel who said the dress 'had to be something that was going to go down in history, but also something that Diana loved'.
It was not without its problems though; the designers had failed to take into account the small glass carriage that Diana travelled in from Clarence House to St Paul's Cathedral with her father. It was so small that there a great deal of difficulty in fitting it into the carriage, and on arrival at the chapel the dress was visibly wrinkled from the travel.
Not only that, but Diana dropped an entire bottle of perfume made by the official royal parfumeur, House of Houbigant - maybe that's why she had the headache.
5. The Cake
The wedding of the century actually had 27 wedding cakes (baked by various bakers including Belgian pastry chef S. G. Sender known as "cakemaker to the kings".
Two versions of the official cake (in case one was damaged) were made by David Avery, head baker of the Royal Naval Cookery School.
They weighed 102kgs and took 14 weeks to make. In 2018 a slice of the official cake was put up for auction and fetched nearly AUD $2000.
No word on whether the buyer has had a taste of it.