Princess Eugenie
Who will Princess Eugenie invite to her royal wedding? Pictured: Princess Eugenie and Jack Brooksbank attend day three of the Qatar Goodwood Festival at Goodwood Racecourse on July 30, 2015 in Chichester, England. Getty Images/Tristan Fewings

Princess Eugenie will invite London socialites to her royal wedding with fiancé Jack Brooksbank, according to a royal expert.

The daughter of the Duke and Duchess of York is set to walk down the aisle in October. And according to royal expert James Brookes, Princess Eugenie's guests may include celebrities and probably one of Prince Harry's exes.

"It's likely the guest list will be filled with London's socialites, and feature a smattering of guests from the art world considering Eugenie's work with Hauser & Wirth," Brookes told Express.

It is also likely that the next royal bride will invite Prince Harry's ex Cressida Bonas to her big day. According to the report, it was Princess Eugenie who introduced the ex-couple to each other. There is no bad blood between the exes. In fact, Bonas was invited to Prince Harry and Meghan Markle's royal wedding and she attended the ceremony.

Following the event, Bonas confessed that for her, the most challenging part of attending weddings is choosing a hat to wear. The actress finds this "tricky."

"Friends are starting to get married, which means the dilemma of British wedding attire. Hats," Bonas wrote. "Why do I find hats so tricky? Tricky to wear, tricky to look at, and extremely tricky for the poor soul sitting in the pew behind. Most of the time I avoid headgear. This can prompt disapproving looks from the older generations."

"Last weekend I attended the royal wedding. The invitation clearly stated that guests must wear hats. Yikes. I opted for a minimal feathered number — and can only hope I got it right," she continued.

In related news, Princess Eugenie recently flaunted a slimmer figure months before her big day. On Thursday, the bride-to-be was spotted at the launch of Pass on Plastic project in London's Carnaby. The royal donned a see-through dress with a black obi-style that showcased her slender frame.

Princess Eugenie has a full-time job as a director at Hauser & Wirth, a contemporary art gallery in Mayfair, London. She has less royal engagements compared to Prince William, Kate Middleton, Markle and Prince Harry, but she's present in some events.