When the stepped out of her car at Westminster Abbey on 29 April 2011 to reveal her Alexander McQueen wedding dress, the fashion world reacted positively. While still romantic and traditional, it wasn't overblown like Diana's, nor was it expected.
Since then, the Duchess of Cambridge has worn the brand on numerous occasions, most recently yesterday evening where she and William joined King Harold and Queen Sonja. She chose a pale pink gown with a cape-style overlay and an embellished neckline. It was princess-worthy, but with an ethereal edge.
Back in Manchester also stepped out , opting for a very different look - a wool tuxedo. Although it shouldn't be news-worthy that a royal-to-be chose trousers for an official engagement, the reality is most members of the firm rarely stray from skirts and dresses after dark - a nod towards tradition and expected conservatism. Markle rejects that archaic notion.
It is interesting that two royal women with such a different sense of style should opt for the same brand. Kate tends to err on the side of side of classic, polished femininity, while Markle prefers tailored separates and unconventional labels that few have heard of. So what is it about McQueen that appeals to both women?
It's important to highlight how different the McQueen aesthetic is today to what it was when its late eponymous founder was running the brand. Throughout the 90s and the Noughties, McQueen was considered a boundary-pushing game-changer. His collections were controversial, rebellious and political and his often macabre catwalk shows were known for drama and theatre - one finale ended with the burning of a Joan of Arc figure, surrounded by a ring of fire, while at another models were covered in torrents of rain.
The designer was famously anti-establishment. When working at Savile Row prior to the launch of his brand, a young Queen sewed 'I am a c**t' into the lining of a suit he was making for Prince Charles.
While his successor, Sarah Burton, has continued with the romanticism, craftmanship and artful tailoring her former boss made famous, it is today a very different brand in terms of how it looks. Burton has moved it beyond its dark beauty, adding a feminine softness that has a mass appeal. It does, however, beg the question - how would McQueen have felt about his brand becoming a go-to for the royal family?
It's unlikely that the Duchess of Cambridge or Markle would have been as keen on the label had its founding designer still been at the helm, creating the poetic, yet deeply dark, subversive collections he was revered for. It is Burton's gentle, softer and serene McQueen that the royals love and the way in which it ticks numerous boxes.
Both Kate and Meghan are expected to promote and wear British designers and, of course, McQueen is among the most famous. There is a sense of occasion to the brand's clothes even today, pervasive in both its dresses and tailoring, befitting of a modern duchess or princess. Take the label's dress coats that the Duchess is so fond of.
It is also beautifully crafted, rich with embroidery, embellishment and decoration (although, Markle steered away from this look with her McQueen tux), again characteristics of royal attire both past and present. There is also something in the heritage of McQueen that could be attractive to the royals - the label has always looked to the past, whether punk, the Dark Ages and the Medieval period, which creates an air of Britishness. Burton's last collection was inspired by England's vibrant and historic country gardens.
The brand today is also very, very beautiful. While its catwalk shows juxtapose femininity with toughness (for example, embroidered flowers on leather or thick leather belts with fine lace dresses), its commercial offering - the designs that make it onto the shop floor - have a more widespread appeal. The pale pink dress Kate wore last night imbued McQueen's signature romanticism without being too directional.
It is certainly a plot twist in the story of McQueen to see it become a royal favourite, but its transformation has ensured its prominence and grown its profile on an international stage. Their endorsement will also have doubtlessly have had a huge impact in boosting sales, such is the Kate and Meghan effect. The royals patronage of the brand - as distant as it is from its founding designer's anti-establishment values - mean that its longevity is solidified.