Wear, what, why, when?

Last week, the Duchess of Cambridge gave birth to a boy. In case it passed you by. It's cause for patriotic pride, singing crowds of the type usually captured in black and white, or the bleary, cheery colour of early Eighties films, circa Prince William's birth in 1982.

Ironically, some see the fact that we have a prince rather than a princess as something of a let-down, a neat inversion of the lust for a male heir that so marked, say, the pregnancies of Henry VIII's numerous wives. Last week, many fingers were crossed in the hopes of a girl – the anticipation of seeing constitutional change in motion via the Succession to the Crown Act.

The well-manicured fingers of fashion editors were no doubt also crossed, in favour of a different kind of succession – because female royals rule when it comes to style. It's difficult to make a fashion fuss about a male heir. Prince George may be inundated with blue-tinged baby attire, but once he hits prep school he's no longer fashion fodder. Look at his mother if you need evidence: every public moment becomes a catwalk, and every item of clothing worn – from a nondescript jersey high-street frock, to a nude court shoe, to a dodgy knitted boob tube dress sported for seconds at a university fashion show – a treasured relic. Said knitted frock cost £30 and sold in 2011 for £78,000. It's difficult to imagine William's old suits making that kind of mark-up.

Kate the Great isn't the first. I personally have a soft spot for Fergie during her Duchess of York years, dressed by Saint Laurent and Chanel (believe it or not, those two labels jockeyed for her sartorial affections). If we're being slightly more po-faced about la mode, Princess Margaret was a true fashion plate, dressed by Dior in her debutante years. “What she wears is News,” said the Picture Post back in 1953 (its capitals). “Seen by thousands of women in person, hundreds of thousands on news reels, millions who read the newspapers and magazines.”

And, of course, there was Diana, Princess of Wales, whose fashion sense – and impact – needs no reiteration.

There's also the enduring, eternal figurehead: Her Majesty the Queen. Dressed in a single colour, to better make an impact in a crowd, and always sporting a hat – a sublimation of the crown. Prince George will eventually be king. But, alas, he probably won't be a style icon.