Now they have another pregnant royal client championing their creations – Zara Phillips, the Queen's granddaughter, was spotted attending a high society ball wearing one of their stunning maternity evening gowns.
"We are delighted that Zara chose to wear Seraphine to the Boodles Boxing Ball," Cecile Reinaud, founder of Seraphine, told HELLO! Online.
"It gives us our second royal stamp of approval this year!"
The silk evening gown in vibrant shades of azure and ultramarine complemented Zara's new pregnancy curves and offset her glowing complexion.
"Zara's statuesque figure epitomises elegance and sophistication, especially suited to maxi gowns and this luxe two-tone maxi is a flattering and striking colour for Zara, as it emphasises her piercing blue eyes and lovely blonde hair," said Cecile.
Talking about what Zara might wear during the latter stages of her pregnancy, Cecile said, "I predict that she will be opting for plenty of sports luxe styles suited to her athletic frame.
"She'd look great in a pair of skinny jeans or luxe leggings, teamed with long-line tunics or layered knitwear and a chic pair of rider boots this winter."
Zara isn't the only high-profile face to sport one of Seraphine's creations this month – heavily pregnant Halle Berry wore their floral silk maxidress as she enjoyed the sunshine with her daughter Nahla in California.