For many, Camilla’s most iconic look will always be from 1970, when she wore a tight red T-shirt and was photographed speaking to a flustered Prince Charles, who had just stepped off the polo field.

Since her marriage to the then Prince of Wales, though, her style has become more formal. Some of her most famous looks include the red long-sleeved dress and hat she wore to the opening of the Senedd (the Welsh Parliament) and the light blue dress with gold detailing she wore in Athens for the 200th anniversary of Greek independence.

There’s also, of course, the silk dress with matching oyster silk coat, created by London designers Robinson Valentine, that she wore to her 2005 wedding to Charles.

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All of this is done with her customary laid-back confidence and self-deprecating humour – and a smile and a nod to the royal photographers. At a preview of a royal photography exhibition at Kensington Palace, I met one of these photographers and he said that Camilla was his favourite Windsor because of how relaxed she is.

Much like the Queen, Camilla is at her happiest in the country and likes nothing more than striding through the fields in a Barbour waxed jacket and a pair of Wellington boots. We rarely see this side of her: walking barefoot with Charles on an Irish beach or looking serious on the back of a horse in riding gear.

Equally, the fashion industry has been pleasantly surprised by how relaxed Camilla is with formal dressing. Her long-time couturier Fiona Clare has worked with her since the 1990s, dressing her for state dinners but also casual daytime engagements, for which she has worn simple black pinafores with silk shirts that have been deemed a fashion success story.

Clare speaks to me on the phone and explains how Camilla is the only client she will travel to see (to Clarence House, the royal couple’s then-London residence, in all likelihood).

Together, they have created some of Camilla’s most stand-out looks, including the white shift dress she wore in 2019 to entertain then US president Donald Trump and first lady Melania Trump, which resulted in that iconic “wink to camera” photograph that sums up much of the duchess’ approach to public life.

“You need to get to know someone when you make clothes for them – it’s a bit like a hairdresser, you need to click with someone and they need to feel really comfortable and trust you,” says Clare. “Camilla and I have found our rhythm. She has really found her style and I think she’s looking amazing.

In the Queen Consort’s case, the right recipe was lots of longer cotton and chiffon dresses, as well as her customary shift numbers with occasion coats on top.

“I think they really work for her,” says Clare. “It’s all about getting the length right. Everything is about balance in midlife, particularly when it comes to your height – the duchess is quite tall [she’s 5 foot 7 or 170cm] so a couple of inches here and there can make all the difference.”

Camilla’s height plays in her favour when it comes to evening dressing – she looks fabulous in ornate Dior or Bruce Oldfield evening coats, or in the streamlined cream or mint-coloured evening dresses Clare has made her.

“The key to not looking frumpy for a smart occasion is pulling out somebody’s good points,” says Clare. “Start with the shoulders and keep details up at the top and then move onto the waist or the hips or whatever part of your body you like the best.

“Then I think about fabric. I work with silk and wool the most, but for more casual occasions I love the Liberty prints [florals that originate from department store Liberty of London] – I used a few Liberty prints on Camilla last year and we got some really lovely dresses out of them.”

Much like Middleton, the Queen Consort regularly re-wears her favourite pieces.

“Oh, Camilla isn’t the type to buy something and wear it once,” says Clare. “Because they’re tailored to her body, they hold their shape for years. Although I can’t take all the credit for how good Camilla looks these days – if you are confident in what you wear, like she is, you will always look great.”