The world watched transfixed when Prince Charles married Lady Diana Spencer in a fairytale royal wedding at London's St Paul's Cathedral in 1981.
But before long, the great love story was shattered by strings of scandals and (more than) whispers of adultery, leading to an official announcement of their separation in 1992.
Yet for the Prince of Wales and the People's Princess the drama was only beginning, and now a royal insider has claimed Diana dealt her estranged husband the most humiliating blow during a banquet at Buckingham Palace in 1993, Express.co.uk reports.
WATCH this video to remember how Diana lived life as a royal rule breaker:
Royal correspondent Ross Benson - who was a school mate of Prince Charles - recalled that after the Wales' split Princess Diana was "banned from every royal occasion", with only the Queen holding the authority to allow her to attend a given function.
Writing in his book 'Charles - The Untold Story', Mr Benson claimed Diana suddenly contacted her former mother-in-law announcing she would attend a state dinner for President Mario Soares of Portugal, leaving the Queen in an unenviably awkward position.
Mr Benson further alleged Her Majesty couldn't bring herself to refuse "for the simple reason that [she] was frightened of Diana".
According to Mr Benson, the monarch was wary of the influence Diana wielded over her sons, Prince William and Prince Harry, and how the future would play out with William as King.
The Princess allegedly arrived to the banquet and stood beside the "husband who detested her" in a final humiliation proving she "outshone him and outmanoeuvred him".
Just four years later, Diana was tragically killed in a car crash inside the Pont de l'Alma tunnel in Paris leaving her young sons without a mother.
Earlier this month, the Duke of Cambridge opened up about how his mum's death continues to affect him to this day.
WATCH this video to hear Prince William's heartbreaking confession:
Alice MurphyAlice Murphy is a freelance journalist and self-professed news addict. Originally from Ireland, Alice is on a mission to visit every country in the world (telling stories along the way). She is most commonly found eating sushi, drinking strong coffee and reading horoscopes.