The Princess of Wales' unmatched elegance and ultra-polished power dressing has provided royal fans with style inspiration for over a decade.
Yet possibly the most endearing thing about the Princess' sartorial influence is that before her enduring love story with Prince William began, she was just a regular university student at St Andrews.
Kate's cool-girl outfits worn in her twenties are well documented, revived in the final season of The Crown which revisited the early flush of romance between the future King and his university sweetheart.
An unearthed photograph of the Princess of Wales at a St Andrews ball has since emerged online, however, with royal fans sharing their excitement at the never-before-seen snap of the then-22-year-old Kate.
"Princess Catherine stunning in black attending a ball at St Andrews in May 2005," shared royal fan account @katemiddletonprincessofwales on Instagram.
In the snap, Kate wears an elegant, plunging black gown boasting a boxy, sleeveless cut and deep-V neckline. The Princess seemed to be wearing neat, pointed-toe heels with her sophisticated gown, adding an ornate chandelier necklace and chunky silver bangles to complete her look.
Kate's chocolate brown hair was worn in silky waves, a far more natural look than her now-famous Princess blowdry and tumbling curls.
"I have never seen this picture before," commented one fan, as another wrote: "I am seeing it for the first time, too. I think it is amazing!"
A third added: "Always stunning. Never seen before either."
The photograph of Kate is an incredibly rare one, especially given the privacy Prince William and his peers were promised during his studies at the prestigious Scottish university.
William's Principal and Vice-Chancellor, Dr. Brian Lang, exclusively told HELLO! how he managed the future King under his care.
He told HELLO!: "One thing that I did as soon as we knew William was going to be a student was to warn the student body that we expected them to respect the privacy of information.
"So, I made it quite clear to the students by doing an interview with the student newspaper, in which I emphasized that we would take a very, very dim view of any inappropriate information being passed on—not just about William, but about any other student."
He added: "Andrew Neil, the Lord Rector of the university, being a very experienced newspaper man, helped us negotiate a deal with the British press, whereby they would leave William alone in return for a photo opportunity once a semester. And on the whole, that worked."
Princess Kate's royal style evolution
The Princess continued her penchant for an all-black ensemble after becoming a member of the royal family, too.
In 2011, the royal looked sublime at the The Sun’s Military Award at London’s Imperial War Museum.
Kate wore a bespoke Alexander McQueen velvet gown, elevated with a rippling velvet fishtail skirt and ruffled tulle bustier.
Levelling up her jewellery from her university days, the Princess of Wales added a dazzling diamond and ruby necklace and bangle from luxury jewellers, Mouawad.