Fashion loves a princess. Five decades before Princess Diana there was Princess Marina of Greece and Denmark, a Cecil Beaton favourite of whom the young Princess Margaret is said to have remarked: “When I grow up, I will dress as Aunt Marina does.” So when Meghan – princess in all but name – boarded a plane to Canada, she left a vacancy. It is probably only a few years now until Princess Charlotte starts wearing Brandy Melville and uploading TikTok videos.

Until then, the ever-conscientious Kate is doing her level best to fill the gap – she has been wearing culottes and everything – but even the Duchess of Cambridge’s most fervent champions would admit that she lacks a little edge.

Enter Princess Anne, the royal fashion influencer who has been hiding in plain sight for 50 years. In 1970, Anne wore a dramatic floor-length evening cloak to a film premiere that – how did we miss this? – was very Gwyneth Paltrow in Tom Ford in 2012 meets Natalie Portman at this month’s Oscars. The power tailoring and Matrix-style sunglasses that Anne rocked at the Chelsea flower show in 2018 looks strikingly ahead of the curve when you compare it with look 41 from Balenciaga’s spring 2020 collection. You have to hand it to a woman who is 18 months ahead of Demna Gvasalia’s Paris fashion catwalk at a horticultural festival not known for its avant-garde dress code.

A pastel suit on the Marc Jacobs catwalk, London fashion week; and Anne in 1973. Composite: Guardian design/Getty Images

Even before her guest appearance presenting this season’s Queen Elizabeth II award to the jewellery designer Rosh Mahtani, Anne was the star of this London fashion week. The Shrimps designer Hannah Weiland namechecked the Queen, Anne and Diana in her lineup of autumn/winter muses, but it was the looks that were most Anne that made the most impact, such as a checked blazer with a dark faux-fur collar, worn with a silk scarf, jodhpurs and sporty sunglasses.

Anne, who became the first royal Olympian when she competed in the three-day equestrian event at the 1976 Olympics in Montreal, has been spending her downtime in sportswear all her life. Her love of jodhpurs aligns her perfectly with the leggings-based athleisure wardrobe of the 21st-century off-duty influencer. Burberry’s equestrian-chic collection this week follows in the steps of the jodhpur-clad riding boots of Michael Kors in New York (see look 6 from Kors’ show for ideal jodhpur-as-trousers inspo, so as fashion embraces tight, sturdy “work leggings” as the cool girls’ alternative to jeans, expect to see Anne’s looks at Windsor horse trials over the years popping up all over Pinterest. The sturdy, knee-length tailoring that Princess Anne has always favoured – more masculine-toned than the Easter-egg pastels of the Queen, boxier than the slender tailoring beloved of both Diana and Kate – was echoed in this season’s new look at Victoria Beckham, where the front row was united in Instagram-love for the tweedy vented culottes worn with a wing-collared blouse and chunky sweater.

Anne wears mustard tailoring in 1983; and a similar look on the Emilia Wickstead catwalk at London fashion week. Composite: PR/PA

The stubborn horse-sense practicality that led fashion to overlook Anne’s wardrobe for decades is exactly what makes it cool. Her off-kilter, retro-tinged colour palette – bracingly unflattering shades of yolk yellow and the lurid cornflower blue of seaside hotel curtains – now looks like a Pantone consultant’s moodboard.

The exaggerated dagger-pointed collars of Emilia Wickstead’s mustard tailoring at her show at the Royal Academy this week were a dead ringer for those worn by Anne at a 1983 visit to Riding for the Disabled in West Yorkshire. Markus Lupfer’s ketchup sweater over contrast polo neck, cinched with a belt over a tweed skirt – look 12 at his London fashion week show this weekend – is straight out of the Anne playbook. Take a look at her at the Windsor Horse Show in 1984, with a blue sweater over a red polo neck and very new-season-Celine flared jeans. And there can be no greater compliments to Anne than that the JW Anderson show, the highlight of London fashion week for many, featured a double-breasted peacoat similar to a longtime favourite of the Princess’s wardrobe. Meanwhile, many of the models at the Marc Jacobs show were remarkably Anne-adjacent in their pastel coats and coloured tights, teamed with either silk headscarves or alpha backcombing.

Royal fact can never quite be untangled from fiction, so in the fashion narrative it is logical that Anne’s style ascent owes something to her recent season-stealing turn in Netflix’s The Crown. Erin Doherty’s Anne has a world-class grumpy resting face, radiating adamantine disdain for the mundanity of life as one of the royal spares, rather than the heirs. These very frustrations have been suddenly spotlit, in recent months, by the very public disenchantment of Harry and Meghan. The zeitgeist has a new princess. With her RiRi-worthy sunglasses and next-season’s must-have jodhpurs, Anne has taken London fashion week by storm.