Sarah Ferguson donned a flapper dress and black headpiece as she attended a 1920s-themed event in Italy on Saturday night.
The Duchess of York was pictured as she arrived at 60th birthday party of Canadian billionaire and socialite Lawrence Stroll.
The themed party - based on F. Scott Fitzgerald's literary masterpiece The Great Gatsby - took place in Villa Lysis on the glitzy holiday isle of Capri.
The 59-year-old was accompanied by a mystery chaperone - leading to fevered speculation as to his identity.
The royal's all-black outfit which featured a cold shoulder cut and paired it with a black headpiece as well as a pair of elbow-length gloves.
She accessorized wearing long earrings and a stylish black cigarette holder alongside her clutch bag.
Prince Andrew's former wife wasn't the only celebrity at the star-studded event, which also featured Hollywood A-listers Michael Douglas and Catherine Zeta-Jones.
Lawrence Stroll, looking resplendent in an all-white suit, led his guests to the celebrations.
The Duchess and Mr Stroll have been friends for years and have attended events together since 2002.
Stroll, 60, has amassed a huge fortune thanks to his investments in high-end fashion brands such as Michael Kors and Tommy Hilfiger.
Some credit him with bringing luxury fashion brands Pierre Cardin and Ralph Lauren to Canada.
The billionaire also co-owns the SportPesa Racing Point F1 Formula 1 team, where his son, Lance, races for his team.
