The bags are decorated using a series of intricate glass buttons created by a veteran glassmaker over five decades from the 1940s to 1980s. The original collection consisted of 40, 000 buttons – Oldfield inherited them all from the glassmaker’s daughter. For the designer, the buttons conjure up images of the artisan’s solitary craftsmanship and elite technical skills – two themes that form the pillars of Oldfield’s couture dressmaking. “The story behind the buttons is extraordinary. I want to give them a new life … I feel honoured to be able to.” The bags are handcrafted in Italy, with prices ranging from £290 to £900.

We talk in the sitting room, a beautiful open-plan space with a balcony displaying pastel hellebores. The golden rays of autumn sunset shine through the windows, illuminating framed artworks, antique mirrors and busy bookcases. The soft scent of leather and Cymbidium orchids infuse the room.

Despite his unconventional start to life, Oldfield was never interested in searching for his biological parents. “Certainly not my father at least. My father wasn’t married to my mother. My foster mother was my mother, until she wasn’t – but she still was. I didn’t have any hankerings to find out. In the late seventies, I did find out some things about my mother and her family …” His voice trails off.

Everyone remarks on the irresistible charm of Bruce Oldfield. He sets down some heavy-looking clothes bags in the hallway and reclines in an aubergine velvet chair. “Are you rubbing all that muck into my brand new sofa, bubba?” he pointedly asks Boo, who has just been for a walk and is using the immaculate velvet sofa as a scratching pad.

It turns out we have Fred and Ginger to thank for Oldfield’s introduction into the world of glamour: “In the 50s, television was a new thing for the masses. We got our first television in 1957 and we didn’t have ITV, just BBC. The TV highlight was the Sunday matinees, particularly Fred Astaire and Ginger Rogers. Those films were only 20 years old at that point.”

Despite a latent hunger for the high life, Oldfield enrolled into teacher training college in Sheffield in 1968. Yet he sensed the world had much more to offer him. “That’s what pushed me on. In Barnardo’s there was this ‘who do you think you are?’ attitude. Look, I’m not what you think I am. I’m never going to be satisfied with what you see as being my future because it’s just too dull. I wanted, and I knew, I could get more. I was always very driven.”

Quickly deciding that teaching was not for him, Oldfield applied for art school, studying at St Martins School of Art. Afterwards, he landed a job at Henri Bendel in New York. It didn’t work out. After four months in the job, having flown to The Big Apple first class, Oldfield was on his way back to England: “It was every budding designers’ dream getting a job like that. It was a shame it didn’t work out, but it couldn’t have worked out because I had no experience. I had no experience of fighting my own corner against management. You have to pick through the advice and criticism. I learnt a lot and I still hold that.”

The conversation segues into Oldfield’s career as a VIP couturier. His first big client was actor Charlotte Rampling, with whom he spent indulgent summers in the south of France in Antibes. “There was lots of scandal that happened there,” he teases. “There I was, with Charlotte Rampling and she had people for lunch like the [French actor] Capucine and the Guinnesses. You learnt how to handle yourself in those situations. I met some wild and wonderful people.”

The passionate heat of the Mediterranean coast seems very far away. It’s a crisp day, which is reflected in Oldfield’s attire. The designer wears a navy cashmere scarf, jumper and trousers with sturdy chestnut brown leather brogues. “I like things that are properly made,” he says. “Like this brass bolt here on this screen,” he says, knocking on a robust folding screen beside him. “The way it moves – I like it. That’s why I avoided [working for] the big conglomerate companies. It was never me. I actually like making clothes and making things properly.”

Fashion in the eighties was a patchwork of styles. In London, Oldfield’s career coincided with the rise of punk, which saw Vivienne Westwood and Malcolm McLaren kick up a storm on the King’s Road. Paul Smith was revamping menswear by fusing classical tailoring with his trademark stripes, while John Galliano was powering to the top of the fashion pyramid with his romantic-historical designs.

The designer points to a photograph of the opening of Gianni Versace’s store on Bond Street in 1992. Versace is front and centre, with Galliano and Rifat Ozbek, Westwood and Oldfield. “Things coexisted quite nicely,” he notes. “Punk existed with the New Romantics, while people like me were dressing all the Royal Family – like Diana.”

Ah, Diana. It’s impossible to summarise Oldfield’s life without inclusion of the People’s Princess. He encountered her first in 1981, when Vogue were curating a wardrobe for the royal-to-be. The magazine selected some of Oldfield’s designs, a handful of which the princess subsequently ordered: “That was just before they got married. We made the [look] she wore arriving back in Heathrow after the honeymoon. She was wearing me. That was it.”

Over a decade, the two formed a close bond. “She was young. She was eleven years younger than me, only 24 at the time. We didn’t have much in common, but we had a good relationship. We had lunches and went to some parties together. But then it ran out in the end in the eighties when she stepped down from being Royal. It was forced upon her.”

He simply shrugs when asked if he minds being known as Diana’s dressmaker. “It’s just the way it is. Now I dress the Duchess of Cornwall. Her dress for the Bond premiere, that was mine. She is lovely. Prince Charles has been my greatest patron!”