In 1997, Gianni Versace was murdered on the steps of his Miami Beach home. His grief-stricken sister, Donatella, suddenly found herself in charge of the family company. Twenty years later, she has chosen to take this anniversary and make it extraordinary, hijacking the style agenda to the extent that fashion journalists have been calling 2017 the year of Versace. She has designed a tribute collection inspired by Gianni’s archives, announced a scholarship in her brother’s name at Central Saint Martins and, in September, in a fashion coup for the ages, reunited Gianni’s supermodel crew – Helena Christensen, Cindy Crawford, Naomi Campbell, Carla Bruni and Claudia Schiffer – for a catwalk finale that melted the internet.

It’s not over. On Monday night, she received a major accolade at the Fashion awards. On Tuesday, she will open a new Versace store on Sloane Street in London. In the light-filled salon where we meet, she is warm and smiley, talking me through a set of unpublished photographs by Doug Ordway that will be exhibited in the store. A lot of her year has been spent poring over old images and old creations, opening up the archive – a 10,000 sq ft storage facility in Novara, near Milan – and examining Gianni’s most famous creations for the first time since his death. “Not in a sad way,” she says, “but a very positive way. I saw what a genius my brother was. To me, he was my brother, but to the rest of the world – such a genius.”

Authentic feel ... Cindy Crawford in the early 90s. Photograph: Doug Ordway/Versace

Even the names of the archive collections, produced between 1991 and 1995, speak of another, more glamorous age: Vogue, Warhol, My Friend Elton, Icons, Baroque. The pictures she shows me are from that time, too, and present the supermodel era exactly as you would want. Here is Bruni, a future first lady of France, dancing with abandon in thigh-high patent boots. Here is a babyfaced, never-off-duty Crawford, smouldering for the camera as she queues backstage. Here is Christy Turlington, running down a beach, wearing only shimmering sequins. Compared with the unsmiling models who have walked the catwalk since, and the airbrushed campaign images and omnipresent filtered Instagram photographs we have grown used to, these pictures feel authentic (however liberally doused in hairspray the models are).

They bring back great memories, says Donatella. “This was the period that fashion became famous,” she says. “It was the beginning of fashion becoming pop culture, of being associated with music and rock’n’roll. Those two worlds were really in contact with one another. When something starts to happen, that is the most exciting moment. It was a huge change. The 90s was a huge change in fashion.

“My brother, of course, was the designer; I was working very closely with him all my life. But I started the relationship with the models that Gianni made ‘super’.” What “super” meant, she says, was showing personality. “Before that, I don’t think many designers let models have personality, nor after. The models should wear the clothes, be very serious, not smile, look in front of you, almost no soul. This was totally opposite: it was about the girls, what the girls were thinking, who they were dating. It wasn’t just about the clothes, but about who was wearing the clothes.”

Backstage sounds a hoot. She speaks in her inimitable, strongly Italian accent, one anecdote rolling into another, about models arriving six hours before the show because they all wanted François Nars, rather than his assistant, to make up their faces. She talks about the models swapping clothes after they had been allocated outfits and thinking: “I don’t know how I’ll explain this to Gianni.” She adds: “What I remember was the professionalism of these women, and the competition, which I think was very good and healthy. Everyone wanted to be better than everyone, not in a bad way.

First lady of fashion ... Carla Bruni in a 1991 Versace advert. Photograph: Doug Ordway/Versace

“My brother was very concentrated about the clothes. I was, too, but my role was to make the girls feel like themselves in the clothes. Would they like it a bit longer or shorter? They were a soundboard.”

Fashion modelling is only just getting exciting again, she says, thanks to technology. “There are two generations of fashion for me: the one before the internet and the one after the internet.” Between the supermodels and now, she says, “was a moment of flatness. Now you could do this picture backstage again – there are people with enough personality there.” She likes the Instamodels, such as Gigi Hadid, who have become powerful thanks to their millions of followers on social media. “I think they are amazing. Very smart girls. Again, finally, we have girls who dare to stand out in the crowd.”

Profile What are the Fashion awards? Show A fixture on the fashion calendar since 1989 (with the notable exception of 1998), the Fashion awards acknowledge and celebrate the finest design and style talent. The event, which is organised by the British Fashion Council, was known as the British Fashion awards until 2016, when it opened up to international fashion brands. It now has only a small number of Britain-focused awards. The categories Specific awards have come and gone – in 2003, for example, awards for sport, acting and music personalities were incorporated. Currently, the accolades up for grabs are: designer of the year; British designer of the year – womenswear; British designer of the year – menswear; accessories designer of the year; business leader; model of the year; British emerging talent – womenswear; British emerging talent – menswear and the Urban Luxe award. Additional awards – including the Isabella Blow award for fashion creator, the Swarovski award for positive change and the special recognition award – are normally announced before the ceremony.

Memorable moments In 1997, designers John Galliano and Alexander “Lee” McQueen jointly took home the designer of the year award for the only time in the event’s history. Nearly 20 years later, in 2015, JW Anderson was named menswear and womenswear designer of the year – another first for the awards.

The venue The awards called the Royal Albert Hall home for the first three years of its existence, before being celebrated at many of the capital’s other most famous landmarks, including the Coliseum, the Natural History Museum and the V&A. In 2016, it returned to its original Kensington Gore address; the plan is to keep it there.

Photograph: Richard Young/REX/Rex Features

Donatella talks about models’ ability to show their humanity as a type of female empowerment. Drawing parallels between models’ power and their treatment in the industry feels pertinent in the wake of the Weinstein revelations. Terry Richardson, who has worked with Versace, has been banned from working with Condé Nast International, while Bruce Weber, another photographer who has collaborated with the brand, has been accused of sexual harassment. The fashion industry is expected to be the next to see many of its titans fall. How does she feel about the wave of allegations against powerful men? She wishes they had come out earlier. “I am very happy they talked,” she says, “but if they came out earlier this thing would stop earlier. But I am very happy they came out.” Has she ever experienced sexual harassment? “No.” There is the first awkward silence of our conversation.

Letting loose ... Helena Christensen modelling for the brand in 1991. Photograph: Doug Ordway/Versace

The 62-year-old’s Fashion awards gong is icon of the year and the hype around her company is enormous, so it is easy to forget the starting point: the horror of her brother’s murder and her first few years running the company, during which she was so shellshocked that she broke down in tears on the catwalk. Does she feel like an icon? “Yes,” she says abruptly, then laughs. “OK, should I be shy? No. This is not because I’m full of myself, but I think, in fashion history, I did a lot. I mean an icon in fashion, not an icon in general, in the world.”

I congratulate her on her self-belief. “Come on,” she says, “after all these years.” For her, an icon is “somebody who can inspire people. I think I can inspire because of my history, which is painful. My brother was killed. He was killed. He didn’t die of anything – he was killed. What I went through as a woman on my own to keep this company alive and overcome all the difficulties, and to be always compared to my brother, who was a genius, when I was not a genius in fashion, I was a different kind of person.” What she did, she says, was to feature rock stars – Prince, Madonna – before anyone else and to get Prince to soundtrack a show. “I’m not saying I cured cancer,” she says. “I am not afraid to go in the middle of the crowd and be one of them. I want to stand out from the crowd, for what I am saying first and also for the way I look. I’m not beautiful, but I have a look: blond hair, high heels, lots of makeup.”

If the look has felt cartoonish in the past, “that was really a shield, to hide myself behind this very cold person that nobody can come too close to me, because I was afraid to show my insecurity, my sadness and my despair for what happened. [It was] so that few people could come and see how I really felt.” Over the past five years or so, she says, “I’ve cut my hair shorter, I wear a bit less makeup – not that much less – [but] I never left the heels; that is something I can be proud of. I walked my whole life in high heels and never stumbled once.”

Her outlandish look has made her one of the few designers to become part of pop culture in their own right. It is one of the reasons why the Versace brand has inspired songs by Lady Gaga, Migos and Bruno Mars. It is why Etsy sells custom-made Donatella Versace dolls and countless T-shirts, phone cases and ringbinders emblazoned with her face. Clearly, she has a cult, camp appeal. Her fans recognise her as someone who uses glamour – not glamour in the sense of looking pretty for men, but in the sense of looking extraordinary – in the face of adversity.

This kind of celebrity brings its own problems. “Fame was not one of the things I was looking for,” she says. “It was more about being taken seriously and being in a good relationship with people I love.” Arguably, as a designer, Donatella never got the respect she deserved until this year. This is partly because the Versace brand is unashamedly form-fitting and glamorous, whereas a great deal of tastemakers expect serious fashion to look serious. The new London store is a case in point, all onyx and Fior di Bosco marble and lustre. The aesthetic of Donatella’s life sparkles, too: Google “Donatella Versace’s bathroom” to see what splendour looks like.

Model pro ... Christy Turlington backstage in 1990. Photograph: Doug Ordway/Versace

Perhaps the biggest challenge is dealing with the fictionalised interpretation of Donatella, which has taken on a life of its own: this version appears as a recurring character on Saturday Night Live, played by Maya Rudolph; it is also embodied by Gina Gershon in the outrageous TV movie House of Versace, in which “Donatella” stashes cocaine in a mascara tube. In January, Ryan Murphy’s American Crime Story: The Assassination of Gianni Versace will be shown on the BBC. The trailer is violent and flashy and seems to suggest that Gianni knew his murderer – the serial killer Andrew Cunanan – which has never been confirmed. Penélope Cruz, who has often worn Versace, plays Donatella; she has said that she spoke “a little bit” with the designer while preparing. “I needed that conversation,” she said. “I really hope that, when she sees the show, she’s going to be happy.” When I ask Donatella about it today, though, she doesn’t seem happy. “I don’t discuss fiction,” she says. So it is a fiction to you? “It is fiction,” she says, her eyes widening for emphasis.

I bring up millennials, the consumer group the industry is targeting most fervently. Millennials are all many designers talk about backstage, particularly in Milan. In Italian fashion, the charge has long been that so many houses have been run for decades by the same designers or dynasties (Armani, Prada, Versace, Missoni; even relative newcomers Domenico Dolce and Stefano Gabbana are 59 and 55) that the scene has become stale. There have been rumours swirling around Versace for the past year or two that Riccardo Tisci, formerly of Givenchy – or Virgil Abloh of Off-White or Kim Jones of Louis Vuitton – might be in line for Donatella’s seat. That may be the case one day, but this year the conversation has shifted dramatically. In many ways, Donatella’s approach to millennials and social media feels remarkably modern – and not only because she has 2 million followers on Instagram (in typically understated style, when she joined the app in 2015, a press release was issued; ever savvy, in her first post, she posed with Gigi Hadid).

This year, she says, has been “a rollercoaster of emotion. Not just that day [of the supermodel reunion show], but preparing for the show, going to the archive and seeing things that I last saw 20 years ago, before Gianni’s death. I never had the courage to go back there, because it was so painful, but I found the strength.” She did it, she says, “for the young generation who didn’t know, who weren’t born when Gianni was alive. I want them to know why Gianni was so important and what Gianni was about.” And to tell her side of the story? “To show them how relevant Gianni is today. No story, no filter.”

The new Versace store is at 179 Sloane Street, London; the Doug Ordway exhibition is open now