On the evening I interview Burberry’s chief creative officer Riccardo Tisci, London has an atmosphere close to boiling point. A stone’s throw away from the brand’s HQ, Boris Johnson has just entered 10 Downing Street for the first time, to jeers from protesters. Anti-Brexit demonstrators roam Parliament Square. Commuters on their way home try to manage the late July heatwave, some with ice lollies, others with pints. Some have given up entirely and are just sitting on the pavement, totally frazzled.

Frazzled is not a word that gets much use at the top of Burberry Towers. The rooftop is all members’ club discretion – bleached wood furniture, bowls of gigantic roses and perfectly chilled, iced sparkling water. The designer has specified this location, where some might have suggested their office, maybe, or a carefully chosen buzzy restaurant. If Burberry is a brand based on a very British weather system of cloudy with a chance of rain, Tisci is different. Born near Lake Como in Italy, he’s accustomed to sunshine.

This becomes clear when he sits down and launches into his summer plans. “I am going to Como to celebrate my birthday,” he says. “Then Mykonos… Me and all best friends who live in different countries, we meet there in August. A nice villa in the middle of nowhere… I love it. If you want to go and eat fish, you go and eat fish; if you want to sleep, you sleep; or if you want to get drunk all together – it’s nice. The sea, the food, the fish, the tomatoes, everything.” These words tumble out of Tisci’s mouth, and he finishes with a grin, and a sip of the iced coffee he arrived with. Anyone after more of this scenario would do well to join 2.5m others and follow Tisci on Instagram. This year’s destinations include a boat in Ibiza (he is pictured topless, wetsuit pulled down to his waist) and New York for Pride (surrounded by friends, all in hotpants). Or look up his 40th birthday in Ibiza – a decadent affair with Kate Moss, Kanye West, Kim Kardashian, Kendall Jenner and Naomi Campbell attending.

‘When you do well for yourself in France you get the Chanel bag, in England you get the Burberry trench’. Photograph: Shaniqwa Jarvis/The Guardian

Today, like most days, the gym-honed 45-year-old – “I am Leo with a moon ascending Gemini” – wears a black T-shirt of his own design with TB (Thomas Burberry) logo, black basketball shorts and well-worn, even slightly bobbly, black Nike socks with swoosh. He carries a Burberry bumbag with a packet of American Spirit peeking out. If you didn’t know he was a designer, you might think he worked in the music industry.

This look signals that Tisci is a departure for Burberry. Google Image Christopher Bailey, the previous chief creative officer for 17 years, and you’ll see what I mean. Bailey is much more a crisp shirt and occasional blazer kind of man, the uniform of the discreetly wealthy. Bailey’s collections reflected this taste, too. They often came with a blue-chip British bookish reference – the Bloomsbury group, say, or David Hockney – and a BBC Radio 6 Music-approved sound: Paloma Faith, Keane, Jake Bugg. Samantha Cameron and Kate Middleton wore the clothes.

And Bailey’s Burberry was successful. Thanks to him, the brand is now Proper Fashion, with the London fashion week show a hot ticket every season. But Bailey’s Burberry was not really cool. Tisci, by contrast, is one of fashion’s current arbiters of that intangible quality. Previously the creative director of Givenchy for 12 years, he designed the wedding outfits for his good friends Kanye and Kim, and has a long-running collaboration with Nike. Madonna, Frank Ocean and Marina Abramović are part of his friendship group (he bought a house with the artist). Since Tisci joined Burberry last year, the brand has worked with MIA (even persuading the edgy musician to appear in the slightly cheesy format of a Christmas advert) and dressed Gen Z favourites Ariana Grande, Rihanna and Gigi Hadid. Such is Tisci’s influence that model Freja Beha Erichsen – who is Kind of a Big Deal in fashion, with 24 Vogue covers to her name and a starring role in Burberry’s autumn ad campaign – rejigged her schedule to be part of this shoot.

Riccardo Tisci with his good friends Kanye West and Madonna. Photograph: Kevin Mazur/WireImage

At Givenchy, Tisci turned a couture relic most associated with Audrey Hepburn’s LBDs into the height of millennial cool – specifically appealing to the hypebeast demographic who might also wear streetwear labels Supreme and Palace. Originally known for his gothic aesthetic, streetwear started appearing on the catwalk around 2011. Hypebeasts swiftly signed up – they loved the T-shirts with a snarling rottweiler print, the basketball vests, the plaid shirt with studs. And at around £360 for one of those T-shirts, they were within reach – more affordable than a four-figure gown, anyway. This was part of the strategy – that, and his duties as a good uncle. “I didn’t want to go home for Christmas and have my sisters’ kids say, ‘It’s beautiful, what you do, but I can’t afford it,’” Tisci explains. “That killed me. I wanted them to come to me and say, ‘I have been saving money to buy the Bambi T-shirt.’

“[At first], nobody was caring about it. Slowly but slowly, it was selling, selling, getting bigger,” Tisci continues. “[Then] everybody wants a piece and everybody starts doing it. I don’t mind it because whenever the younger generation talk about that, they always mention my name.” Tisci’s success meant high street brands started producing their own take. You might not know his name but he is the reason you have a statement sweatshirt, the reason the phrase “posh tracksuit trousers” is not an oxymoron.

Reworking the check. Tisci’s Burberry designs bring the classic to the radar of a new generation.

It’s no wonder, then, that Tisci is intrigued by a part of Burberry’s history that was, until now, a touchy subject: its association with “chav” culture. In 2002, actor Danniella Westbrook was snapped in a Burberry check skirt with matching handbag. Her daughter wore a matching kilt, and sat in a Burberry check pushchair. The label was also spotted on football terraces. By being associated with the working-classes, the luxury brand was seen as losing its way. While check had already been reintroduced by Bailey, with a 2018 collaboration with streetwear designer Gosha Rubchinskiy, Tisci has reassessed the idea of “chav”. “I know I shouldn’t say it, but last season it was a little bit the inspiration,” he says. “I think it is great because I come from the streets.” The AW collection, entitled Tempest, included streetwear, sophisticated classics and that oh-so-familiar check, reworked with a darker khaki and the punchy graphics that Tisci fans flock to.

Designers from humble backgrounds are nothing new – Alexander McQueen, Vivienne Westwood, Bailey himself - but Tisci has a genuine rags to riches story. Born in 1974, he grew up the youngest child – and only boy – of nine children. He wore his sisters’ pink hand-me-downs to school. His father died when Tisci was four and the siblings had to work to keep the family afloat. He has spoken before about one meal a day being the norm, how he was helping his uncle with plastering from the age of 11. It’s all a long way from rooftops with a view of the Houses of Parliament.

Tisci’s unlikely success is, he says, down to “angels I have crossed in my life”. The first arrived when he stopped attending primary school. “The teachers came to my house, Miss Besio and Mr Borriero. They said to my mum, ‘Your son needs to study because he has something different to all the other children.’” Tisci stayed in school. This continued in London – on an internship, fellow designer Antonio Berardi saw his illustrations and sent Tisci to renowned fashion college Central Saint Martins. While there, tutor Willie Walters ensured he received a grant so he was able to study. Tisci was made creative director of Givenchy in 2005, aged 29. “I am a self-made person,” he says now, with a drag of an American Spirit. “My mum gave me love but that is the only thing she gave me.” (Tisci is prone to these telenovela-ish soundbites, which is understandable when you find out he has a story worthy of a box set.)

Rihanna wears a Burberry trench on stage at a Fenty Beauty event. Photograph: Mark Ganzon/Getty

Tisci sees a kindred spirit in Thomas Burberry, who started the eponymous brand in 1856, at the age of 21, in the far from fashionable environs of Basingstoke. He invented gabardine, the waterproof fabric that went on to be used for the trenchcoat, in 1879. Adopted by explorers and intrepid types including Ernest Shackleton and Betty Kirby-Green, Burberry trenches were worn in the trenches in the first world war. By 1965, it’s said that one in every five coats exported from the UK was made by Burberry. These days, the brand employs around 10,000 people and is the only luxury fashion brand in the FTSE 100. It also looms large in British style. In the time I have been working on this interview, I have seen Tisci-designed Burberry tote bags on the tube, the check on a woman’s scarf in the supermarket, a trench, with rolled-up check sleeves, in a cocktail bar.

Tisci says Thomas is central to his reworking of Burberry, so much so that he changed the Burberry logo – with the help of Peter Saville – to feature the founder’s initials. “The company should still be an institution but at the same time we need to have the perception of human,” Tisci says. “It’s not only a business company.” That may seem a bit soppy to any board members reading this, but his nose for hits is well-known – Burberry’s share price went up 5% when his appointment was announced. There’s still work to do, though: even after a 4% rise in sales, analysts at the Bernstein Group downgraded Burberry to “underperform” in August.

Tisci’s track record for courting millennials suggests this is just a blip. He’s started Burberry’s B Series which plays into the “drop” culture of streetwear – a new product is released on the 17th of each month (August’s was a dog hoodie, personalisable with the lucky pooch’s name), and reliably sells out in minutes. Another addition is T-shirts, scarves and bags covered in unicorns. If that sounds like a cynical ploy to appeal to fans of emojis and pool inflatables, the story has the authenticity this cohort highly prizes. A search of the archive revealed an alternative insignia from the brand’s famous knight – a unicorn, designed by Burberry for his family. “In the day it was a horse, in the night it became a unicorn,” Tisci says. “I thought it was a very beautiful thing. In a way, it’s very relatable to what happened in my life… My sisters were like Thomas Burberry. During the day, they have to be strong warriors, but in the night they would take off all this armour and be very sweet mothers to me.”

Family comes first for Tisci. He remains very close to his mother, who is now 90. His formative experiences of fashion came from watching his eight sisters – who, he says, are four pairs of best friends – get ready to go out, when he was a child. “They would be in the bathroom, putting makeup on. I was sitting on the bathtub thinking, one day I can go out and meet the people around the world.”

Tisci has said before that he took the Givenchy job so he could buy his mother a house. His break with the brand was also prompted by family – at the funeral of his brother-in-law in 2016, he realised his mother was getting older, his nieces and nephews were growing up. And he wanted in. “I wanted to be the son of my mother, the brother of my sister, that I have never been really because life never gave me the opportunity,” he says. He quit Givenchy the following spring. The announcement went out while he was in a desert in Algeria, with his phone switched off.

Sitting back. Model Freja Beha Erichsen wearing Burberry. Photograph: Shaniqwa Jarvis/The Guardian

The next year was low-key. He had, he says, “no agenda”. “Like anyone when you are busy, you have a PA, a PR,” he says. “Sometimes you want to go to buy your toothpaste, you want to discover what is the new cream for your skin, not always have somebody going for you.” He slept a lot and he travelled, going to Portugal with his family and backpacking around Costa Rica. That is, until Burberry called. Tisci was brought back to fashion by the man who brought him into it in the first place – Marco Gobbetti, now CEO of Burberry (with an annual salary of £7.3m, as was recently revealed), but then at Givenchy. “Marco is the person who saved my career and gave me the opportunity to be who I am today,” Tisci says, with that frisson of drama. The trench was also enticing. “When you behave well at school, in France you get the Chanel bag,” he says. “In England you get the Burberry trench. It’s something I discovered here. Adele told me the first thing she bought when her first single came out was a Burberry trench.” Tisci’s first collection for Burberry featured 20 trenches.

But will the perception of a brand – and an item – so associated with Britishness change post-Brexit? “British is not my culture but I am representing a very important British house,” Tisci says. “For me to celebrate Britishness and bring it to America, China, it’s very important.”

I would guess Tisci was Remain – inclusivity and diversity are his MO. He championed casting people of colour well before the rest of fashion woke up to the idea. He also cast his friend Lea T, a trans woman, in an ad campaign in 2010, helping her financially and opening the door to models such as Hari Nef, Andreja Pejic and Nathan Westling. “I got so much shit. You cannot imagine,” he says. “Thank God we had people like Oprah Winfrey who said, ‘Stop a second, he is doing something that is right.’ When somebody more powerful says something, it changes.” Family Tisci were a support network, too. “When she [Lea T] decided to become a woman and her family didn’t accept her, my mum took her to our house and she lived with us,” he says. “She treated Lea as a daughter. Lea still says, ‘Your mum is the first person to call me she, not he.’”

Tisci is definitely an ally to a socially aware generation (Burberry’s policy of burning clothes and its use of fur ended soon after he joined). But he doesn’t always get it right. There was a skirmish after the autumn show when model Liz Kennedy compared the fastening on a hoodie to a noose on social media. “Suicide is not fashion,” she wrote. “Riccardo Tisci and everyone at Burberry it is beyond me how you could let a look resembling a noose hanging from a neck out on the runway.” While other brands have seen items that cause offence reach stores – both Gucci and Prada have had scandals around designs with racist imagery – this was swiftly shut down. In a statement, Tisci said, “It does not reflect my values nor Burberry’s and we have removed it from the collection.”

The good ship Burberry: Tisci brings a twist to Burberry’s heritage with graphic prints and a new logo. Photograph: Shaniqwa Jarvis/The Guardian

While Tisci says he isn’t a political person, he does concede he has a platform. “If it’s to fight for rights, to help people, I am the first one,” he says. “If it’s about going to sit at a table and talk about money, numbers and power, that is, like you say here, not my cup of tea.”

Now back in London for over a year, Tisci lives in Mayfair (he did consider Marylebone, where his friend Madonna has a house), trains every day in a local gym and watches what he eats. Then, once in a while, he lets himself go. Tisci has gone to raves, festivals – “I never thought I would be a festival person” – and gigs: Rosalía, the buzzy Spanish singer, Björk, Primal Scream. The evening we speak, he is having drinks with singer Dua Lipa. Next up, his birthday, celebrated quietly with family. I’m not taking his word for it – it’s all documented on Instagram a few days later. The designer looks content, lake in the background, Aperol spritz on the table, surrounded by his sisters and mother. Rooftops in London are all very well but for Tisci, there’s still no place like home.