- The Duchess of Cambridge knows the most important rule of royal wedding dressing is not to upstage the bride.
- That's according to royal correspondent Camilla Tominey, who says that it's tradition for royal women to rewear outfits they have already been photographed in to weddings.
- Kate Middleton rewore a dress she had worn twice before to Meghan Markle's wedding in 2018, and at Princess Eugenie's wedding later that year she wore a dress strikingly similar to the one she wore to Trooping the Colour.
- Another tradition Middleton has followed involves wearing something designed by her own wedding dress designer, Alexander McQueen.
- Markle also wore a Givenchy dress to Eugenie's wedding, which took place just five months after her own.
- "It's a way to show some nostalgia for their own days without overshadowing the bride," royal commentator Kristen Meinzer told Insider.
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As soon as Princess Beatrice announced her engagement to Edoardo Mapelli Mozzi in September, fans started speculating on what the wedding will be like — where and when in 2020 it will take place, and what royals like Kate Middleton will wear to it.
However, the answer to the last question could be easy to predict.
The Duchess of Cambridge has made a habit of rewearing old outfits or similar styles she has previously been photographed in to royal weddings over the years.
For instance, she wore this Alexander McQueen coatdress to Prince Harry and Meghan Markle's wedding in 2018, after already having worn it twice before to Princess Charlotte's christening in 2015 and the Trooping the Colour parade in 2016.
She wore another Alexander McQueen gown to Princess Eugenie's wedding in October the same year, and fans noticed it was strikingly similar to one she wore to the Trooping the Colour parade the year before.
According to royal correspondent Camilla Tominey, this is a tradition royal women follow to ensure they don't "upstage the bride."
"We'll have to keep an eye on Kate and Meghan because traditionally they wear outfits they have already worn before," she said on "This Morning" ahead of Princess Eugenie's wedding last year.
However, according to royal commentator Richard Fitzwilliams, the rule is far more simple than that.
"The only rule is the same at all weddings," he told Insider. "Wear something chic, royals are expected to be chic and it goes without saying that no one should upstage the bride."
Another thing worth noting is that both dresses were Alexander McQueen, the same designer who created Middleton's wedding dress for her own royal wedding to Prince William back in 2011.
While Meghan Markle didn't rewear an old dress to Eugenie's wedding, she did pay tribute to her own wedding dress designer by wearing a Givenchy dress to the ceremony.
"Tradition may be overstated, but it's something that both Kate and Meghan have been known to do, most recently at Eugenie's wedding," royal commentator Kristen Meinzer told Insider.
"It's a way to show some nostalgia for their own days without overshadowing the bride. After all, it's just them wearing their favorite designer again," she added.
It's impossible to predict exactly what Middleton and Markle will wear to the next royal wedding. However, both have recently been spotted at royal engagements wearing outfits by their wedding dress designers, so these could definitely be good options.
Middleton wore this green Alexander McQueen coat to St Patrick's Day in 2019.
Meanwhile, Markle wore this one-shoulder Givenchy gown to the British Fashion Awards last year.
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