Princess Eugenie, 28, is tying the knot this week at St George’s Chapel with her fiancé, Jack Brooksbank.
The wedding will be attended by members of the Royal Family, as well as Jack and Eugenie’s A-list friends.
The occasion will be perhaps even more special for one wedding guest, Meghan Markle, who had her own wedding at the Chapel earlier this year.
Entering the church as a guest, not the bride, what will Meghan wear? And will she be bound by any royal protocol?
Much speculation has been had on what Meghan will wear on the big day, with odds even released by betting agency Ladbrokes.
The odds pointed towards Meghan wearing a creation by one of her favourite designers, Givenchy.
Her own wedding dress was designed by Clare Waight Keller for the French fashion house, and she is often spotted wearing its designs.
The odds for the Duchess wearing the French designer are 1/3, with Jessica Bridge of Ladbrokes saying: “It may well be Princess Eugenie’s big day, but she’ll also have to share the limelight with The Queen, Kate and Meghan.
“Attention is quickly turning to their outfit choices ahead of Friday’s spectacle.”
Royal protocol could also play a part in what Meghan will wear on the day.
Yesterday, a royal expert appeared on ITV’s This Morning to discuss the boundaries that Meghan and Kate face when deciding on a wedding ensemble.
Speaking to Holly Willoughby and Philip Schofield, associate editor for The Telegraph revealed the Duchesses will have some strict rules to follow.
The royal journalist revealed it is traditional for Kate Middleton and Meghan to actually wear outfits they have already worn.
She revealed: “ “This is so they do not upstage the bride. Don’t be surprised if we see Meghan in something she has worn recently.”
Camilla revealed that it’s a rule often followed by Kate in order to not upstage the bride, even at private weddings.
Who is Meghan Markle? Quick profile
Meghan Markle was born Rachel Meghan Markle, on August 4, 1981 to parents Doria Ragland and father Thomas Markle.
Her father was previously married to Roslyn Loveless and Meghan has two elder half sibling – sister Samantha Markle and brother Thomas Markle Junior.
Meghan’s first television appearance in the USA was in an episode of the medical drama General Hospital in 2002.
She later moved on to roles in CSI, Without a Trace and Castle along with bit parts in Hollywood films including Get Him to the Greek, Remember Me and Horrible Bosses.
Meghan was also a “briefcase girl” on Deal or No Deal – but her most famous role was as Rachel Zane in legal drama Suits, which launched in 2011.
She was written out in the finale of the seventh series when her character got married, which aired in April 2018 – just before she got married herself.
Charity and humanitarian work
Meghan Markle’s career in television has gone hand-in-hand with her support for causes close to her heart.
She wrote about the stigma around menstrual health in an article for Time magazine and was a Global Ambassador for World Vision Canada – with whom she travelled to Rwanda for the charity’s Clean Water Campaign.
And her commitment to gender equality has seen her work with the United Nations – receiving a standing ovation in 2015 for her speech to mark International Women’s Day.
In September 2011, she wed film producer Trevor Engelson, who she began dating in 2004.
But the pair divorced two years later in August 2013, citing irreconcilable difference.
She was in a relationship with celebrity chef Cory Vitiello for almost two years, before they broke it off in 2016 but the two remain good friends.
And in June 2016, she met Prince Harry on a blind date set up by a mutual friend.
Their relationship began in October that year and just over one year later, on November 27, 2017, the pair announced their engagement.
They married on May 19, 2018 at St George’s Chapel in Windsor Castle.
Some have claimed Meghan Markle is the first mixed-race member of the Royal Family.
Historians are still arguing about Queen Charlotte, the wife of King George III.
But Meghan will be the first royal to openly embrace a mixed-race heritage.
She has written about the difficulties of being a biracial actress in Hollywood as she claims she is not black enough for some roles and not white enough for others.