Katharine Worsley, 90, married Prince Edward, Duke of Kent, 87, on June 8, 1961, at York Minster.
The new Duchess of Kent wore a wedding dress designed by the Irish designer John Cavanagh.
This decision was made on the advice of Princess Marina, Prince Edward’s mother, as Mr Cavanagh had trained under Edward Molyneux, the designer of her own wedding gown from 1934.
The dress was made of 217 metres of white patterned silk, featuring a high scooped neckline, long sleeves and a fitted waist.
The full skirt was covered at the back by a 15-foot double train. However, there was also a hidden feature in the dress that hardly anyone knew about at the time.
A few stitches at the hem of the gown were intentionally left unsewn due to the superstition that it is lucky to leave some part of a wedding dress unfinished, according to reports.
The new Duchess wore a tulle veil and a diamond bandeau-style tiara which had belonged to her husband’s late grandmother, Queen Mary. The Queen purchased the diadem from Garrard & Co in 1925.
Both Katharine and Princess Marina were concerned that her wedding dress appeared massive in Mr Cavanagh’s studio.
However, the designer reassured the duo that the scale would fit York Minster, the wedding venue.
There was also concern the dress was too heavy and would be awkward to manoeuvre.
To help with this, Katharine practised walking, curtsying and kneeling in the dress with Mr Cavanagh’s help prior to the wedding.
Prince Edward and Katharine broke with royal convention when they chose to tie the knot at York Minster, rather than continuing the long-established tradition of marrying in Westminster Abbey.
It was the first royal wedding to be held there in over 600 years.
Prominent royal couples like the late Queen Elizabeth and Prince Philip, the Prince and Princess of Wales, and the Duke and Duchess of York all married at Westminster Abbey.
However, other royals such as the Duke and Duchess of Edinburgh and the Duke and Duchess of Sussex also opted against marrying inside Westminster Abbey.
Both couples, along with Princess Eugenie and Jack Brooksbank, married at St George’s Chapel in Windsor Castle.
Similarly, Princess Diana and King Charles married at St Paul’s Cathedral, and Princess Beatrice and Edoardo Mapelli Mozzi married at the All Saints Chapel in Windsor.