It's unclear if any other woman has made a similar sartorial choice in the past and dared to wear a suit to a royal wedding, but based on the reaction to Delevingne's ensemble, expect to see a lot more women in tuxedos when summer wedding season hits.
It was the same setting as the lavish wedding in May of Prince Harry and his American actress wife Meghan. About 200 fewer individuals were invited to the Duke and Duchess' nuptials.
"It was love at first sight", Princess Eugenie told This Morning.
The couple showed clear signs on nerves but beamed happily during the hour-long service. Prince Andrew called Brooksbank "an absolutely outstanding young man.I'm really thrilled for them".
Princess Eugenie was the ideal bride on Friday as she married her beau Jack Brooksbank.
But Prince Andrew thinks his daughter's wedding day will be better because Eugenie and Jack. have more friends.
As she arrived at the wedding alongside her brother, Prince George, who was also in the wedding party, she excitedly waved at the crowds like a total pro.
Eugenie's elder sister Princess Beatrice, the maid of honour, read a passage from the The Great Gatsby describing the smile of the title character, a rich man famed for throwing parties for the 1920s NY glitterati. The pair met on a skiing vacation in Switzerland in seven years ago, and Brooksbank proposed in January when the pair were in Nicaragua.
Princess Eugenie, granddaughter of Queen Elizabeth, marries on Friday in the second major royal wedding of the year at Windsor Castle, following in the footsteps of her cousin Prince Harry and his wife, Meghan.
A smattering of celebrities are expected to be among the guests with the daughter ex-Take That singer Robbie Williams one of the bridesmaids. Poignantly the father of the bride then waited by the castle door (top left) and held her train (main picture) as she climbed into a rare DB10 Aston Martin with the help of older sister Beatrice (right).