It's easy to forget quite how influential Princess Diana was from the day she joined the royal family in 1981 until her death in 1997. Even for a republican blow-in like me, a student fresh from Ireland with stronger style leanings towards Patti Smith than a pie-crust collar, she was bewitching. And our fascination for everything she did and how she looked only grew stronger as she got older.
How we imagine she might look today as her 60th birthday approaches is challenging when our image of her is frozen as the 36-year-old making a new life for herself post-divorce. But the style experts behind the scenes who helped her on her path are in uncharacteristically strong agreement (for fashionistas) about where her style evolution might have brought her today.
The most photographed woman of her time, she dominated the covers of newspapers and magazines in large part because she was really engaged with fashion.
Mentored by Anna Harvey, the chic and famously discreet deputy editor at Vogue, the Princess of Wales' wardrobe evolved from the "one long dress, one silk shirt, one smart pair of shoes" she owned when she married to an era-defining collection of the best of British fashion design of the time: Bruce Oldfield, Catherine Walker, Zandra Rhodes, Jasper Conran, Rifat Ozbek, Stephen Jones.
Sam McKnight and Mary Greenwell were the hair and makeup team on the cover shoot for Vogue which saw her emerge from mop-haired Sloane to charismatic princess.
Her Bruce Oldfield evening wear powered her graduation to fully fledged glamour puss. And with Jasper Conran she shared a love of simple shapes and head-turning colour.
This "A-team" agrees she would have continued to defy categorisation. Don't imagine you've nailed this guessing game if the best you can come up with is "glamorous granny" or "mid-life maverick". The princess was never one to follow trends but she was always a trailblazer.
Whether visiting hospital wards or war zones, shining at school sports day or making keynote speeches at a podium, her style was always perfectly in keeping with royal protocol but she never let strict adherence to any rule book obstruct her message.
Diana's wardrobe was always contemporary and, while it reflected the stages of her life and growing confidence, her understanding of her personal style rather than fashion was a reflection of her sincerity and her comfort knowing who she was. There is definitely a lesson in that for all of us.
'She couldn't help but be glamorous' - Jasper Conran
I know exactly what she was planning with her life. After the trip to Angola to support the banning of landmines she knew she could take serious issues and tackle them.
She was learning how to present and how to speak in front of a camera – all aspects of journalism, in fact. And she would have been making films and documentaries, using them as a platform to support her campaigns. She intended to be a serious person and use her influence.
Diana went to the gym every day and didn't drink so she would have aged very gracefully. She'd have taken a good look at those plumped up society faces and probably thought "best not".
The princess had accepted that she would never be free of press attention but if that was what she had to live with - then she was going to use it. It's easy to forget how brave it was of her to sit at bedsides in an Aids ward without gloves or mask. People were terrified at the time. She knew she could take on the big issues with empathy and humanity. And she was going to really go for it.
And, of course, she would have been unbelievably placed to do this. There would still have been the gala dinners. She couldn't help but be glamorous. But she wanted to be taken seriously on a global stage and her presentation would have reflected that.
Think Barbara Walters - turbo charged. It would have been gobsmacking what she was going to get up to.
'Diana loved to look good but she wasn't vain' - Sam McKnight
It's strange to think how she would be today, but I suspect that she found her mojo in the 90s. I'm sure she would have kept fit, so some of those fabulous pastel Versace suits or Catherine Walker dresses might have made a reappearance for sustainability's sake!
By the mid-90s she was no slave to fashion. Her sleek, chic, sharp new look meant business. And she loved her sportswear for the gym. I like to think she'd have continued in a similar unfussy, classic vein, honing her sharp eye for a good colour scheme.
Diana loved to look good. And she worked quite hard at it, as much out of respect for the public as for herself. She wasn't vain. It was all about staying healthy and fit. She knew that health was the key to confidence and great looks. She was way ahead of her time with alternative therapies and her daily fitness regime, and would have continued to be a great advocate of wellbeing.
I'm not sure if the princess would have embraced the grey hair trend, though. She loved, and rightly so, those glorious blonde highlights.
'With those long limbs she could put anything on and look great' - Mary Greenwell
Princess Diana loved the beauty world but she wasn't vain.
As she approached her 60th she might have succumbed to a few tweakments (like we all do) but I feel pretty confident saying she would have drawn the line at plastic surgery.
There is a huge difference between the skinceuticals that are available now and actual surgery. The first improves the tone and texture of your skin. Surgery: changing the fundamental structure of one's face? No, I don't think she would have gone there.
Going grey is another issue. I've gone pink to manage mine. I don't imagine she would have done that. If she had gone a good grey, why not let it happen? But all grey needs help. Nobody is completely natural now. She was a woman who took care to exercise, eat well and stay fit. And I have no doubt that she would have continued to look after herself.
She always dressed simply and appropriately, as much out of consideration to those around her as for herself. The Patrick Demarchelier pictures in Vogue gave her confidence and helped her develop her look. They made her aware of her own beauty in a way that she wasn't before. She was a great clothes horse with those long limbs and could put anything on and look great. So, I don't think her style would have changed too much. It wouldn't have needed to.
In relaxed moments those jeans and white shirts would still be looking good. And her simply tailored dresses and jackets were and continue to be timeless.
'She'd be giving the politically correct crowd a run for their money'- Bruce Oldfield
Well she would certainly be teaching today's activists a thing or two. She'd be a role model for all of them but she would have developed a sense for who was sincere and who was in it for self-promotion and she wouldn't have had any patience with that lot.
And she wouldn't be pussyfooting around some imaginary set of rules. She'd be giving the politically correct crowd a run for their money.
She had a wicked sense of humour and a great capacity for empathy and I think by now she would be so secure in her position and so confident in her achievements that she would be outspoken to the point of bluntness.
It would all be in an effort to get things done. I think she'd have learned to care much less about what people said about her or thought about her and she'd not give a thought to whose feathers she was ruffling as long as she achieved her purpose.
Diana was a sun-worshipper so, at 60, she might be dealing with the price paid for those golden tans. But her sisters and mother aged elegantly so there is no reason to imagine she would have been any different. I see her like a Lauren Hutton or Audrey Hepburn character: unashamedly and proudly the age she is and not even trying to pretend to be anything else. It certainly would not have stopped her enjoying sport and fun in the sun.
I think she might have become less interested in clothes only because she might have started to worry that being a fashion plate might undermine her status as a serious player. It would have become intensely frustrating to her to address the UN and have the coverage led by what she wore.
So she might have brought some of her collection of gowns back from some creative re-modelling for the sake of sustainability and to show people she had her feet on the ground. If pushed to choose between fashion and philanthropy, it would have been the philanthropy that won.