It has been almost 40 years since Lady Diana and Prince Charles walked down the aisle in one of the most televised events in royal history, often dubbed as the 'wedding of the century'.
The Fairytale Wedding

Emka74/Shutterstock | Prince Charles and Princess Diana’s wedding cost $110 million
The couple tied the knot on July 29, 1981, in front of thousands of spectators. The nuptials seemed like a page ripped out of a fairytale book, even though their relationship was anything but a fairytale.
The lavish wedding, that took place at St. Paul's Cathedral with over 3,000 guests in attendance, cost the family $100 million -- all paid from the taxpayer's money, of course.
According to reports, 750 million people around the globe had tuned in to see Diana step out of the car in her iconic wedding dress that had people talking for years to come.

Mark reinstein/Shutterstock | Princess Diana's wedding dress broke many records
But what was it about the gown, besides its big puffy sleeves and long train, that broke so many records? Here's what sets Diana's wedding dress apart from any other ensemble donned by a royal bride.
Record-Breaking Train
When it came to designing the dress of her dreams, Diana tapped David and Elizabeth Emanuel, former husband, and wife who ran a design company together back in the day.
The dress was so poofy and over-the-top that it was hard to take eyes off of the 25-foot-long train which is the longest in royal wedding history, but the dress had several other subtle elements that you might have missed.
For one, the dress was embellished with intricate embroidery and 10,000 pearls, finished with a tulle veil that stretched to 153 yards. Her massive train was even longer than Denmark's Princess Sophia's, which measured 20 feet.
Mystery Behind the Backup Dress
With a wedding as grand as that of Prince Charles, who's next in line to the throne, the royal family had to make sure that nothing went amiss on the special day. This meant creating another dress as a backup in case the press got a whiff of the design before the wedding day.

Andrew Crowley | The designers made a huge effort to safeguard the wedding gown, even hiding it in a high-security safe
The designers made a huge effort to safeguard the wedding gown, even hiding it in a high-security safe and making sure that the princess had a plan B in case the design of the original dress got leaked.
Unfortunately, the backup dress mysteriously disappeared so we'll never get to see what it actually looked like.