Princess Eugenie will have to follow a particular royal tradition for her wedding to Jack Brooksbank at St. George’s Chapel, Windsor Castle.
It involves carrying a certain plant on her wedding day which is customary of all royal brides, including most recently Meghan Markle, 36.
Her bouquet must contain a flowering plant called myrtle, according to the decades old custom. Meghan also carried myrtle when she married Prince Harry earlier this year.
The royal rule was revealed by Grant Harrold, a former butler in the royal household.
He said: “I am sure Eugenie will have the traditional sprig of Myrtle in her bouquet from Queen Victoria’s myrtle bush.”
“The myrtle used is from a plant used by Royals since Princess Alexandra.”
“It has also been used in the bouquets of The Queen, Diana Princess of Wales and The Duchess of Cambridge.
The famous myrtle plant is based at Osborne House, the former home of Queen Victoria in Isle of Wight.
But this isn’t the only tradition Eugenie will have to follow on her wedding day.
Royal tradition will also dictate the colour she must wear, according to Grant.
“The royal bride will wear the traditional white or cream dress as Royal brides have done over the decades.”
The wedding dress itself will be a secret until the big day,” he added.
“But I have no doubt her mother, Sarah Duchess of York will be keeping her right with this and a lot of the planning of the big day.”
Earlier this week, Princess Eugenie’s former stylist admitted Sarah Ferguson has a strong influence over Eugenie and Beatrice.
Stylist Charlie Anderson, who worked with the princesses for a year in 2012, revealed the Duchess of York has a strong influence over what they wear.
“She loves fashion and has strong opinions on what the girls should wear,” she told People magazine.
“The Duchess looked amazing at Ascot, as did both of the girls.”
So what does Charlie think of Eugenie and Beatrice’s fashion now?
“I think they are mostly getting it right,” said Anderson.
I think they have got more daring, although they have both always been quite daring and they seem to be getting to know themselves better.”