Its founder, Jet Shenkman, was inspired by her mother’s cashmere twinsets and Hermes scarves before falling into fashion while living in Japan in the 80s.
With her traditional routes and outward-looking interests, perhaps it is little surprise she went onto become a favourite of the world’s most modern royal.
The family business is run by Jet and her daughter Nina and with their shop and couture studio a 15-minute walk from Kate’s Kensington Palace home it is a great location for royals and London’s wealthiest shoppers alike.
Kate’s most recent outing in Eponine London was earlier this week to promote her Hold Still photography book.
It was a green wool boucle dress with three-quarter sleeves and pockets.
However, this piece appears to be a couture adaptation of a pink dress by the brand, with a narrower skirt and in a different hue.
So, how does Eponine London’s couture service, of which Kate is such a fan, work?
Couture customers will have a consultation at the Kensington studio. At said consultation, the customer and designer will look through selections of samples, fabric and colour swatches, as well as discussing what they want.
The customer’s measurements will be taken for the ideal fit.
One to two extra fittings will take place to make sure the piece is perfect.
At the end of the process, customers will take home their perfect item. Prices per garment start at £2,300.
Ready-to-wear items from the brand cost in the region of almost £600.
Kate is not the only aristocratic woman who loves the Eponine brand.
Actress and ex-girlfriend of Prince Harry, Cressida Bonas wore an Eponine gown to the Duke’s wedding to former actress Meghan Markle.
The stunning gown was made with colorful fabrics Eponine sourced from north Thailand.
Actress Helen Mirren has worn Eponine on the red carpet, while Holly Willoughby has worn the brand to present This Morning.
Kate wore an old favourite blouse with a special family meaning recently.
The Duchess of Cambridge wore a £125 Whistles blouse.
The blouse appeared over 10 years ago in Kate and William’s engagement photoshoot.