John Frieda became a celebrity stylist in the 1970s, although he would probably take issue with part of that statement, insisting that it was his then wife, Lulu, who was the celebrity. But even in those days, fame was contagious. Actually he’d take issue, period. Partly, I think, because he likes to lead his life with a quiet dignity, and partly because, like many autodidacts, he’s got his serious streak.

But the salient point here is not how very famous or rich Frieda is. (He’s richer than Charles Worthington, who sold his product company for £20 million, and richer than Vidal Sassoon, who sold his for £30 million – he crops up in the Sunday TimesRich List 2007 with £190 million). Nor that his favourite book is The Fountainhead (the cult read of every architect, it’s a paean to individualism and two days after our interview, a copy of it, along with the Bhagavad Gita, arrives at my house from Frieda). The point isn’t really even that a bottle of Frizz Ease, the brilliantly named and gratifyingly effective serum that launched it all back in 1992, sells every five seconds.

No, what strikes the casual observer is how young he looks for someone who worked with David Bailey, Barry Lategan and Clive Arrowsmith in the days when they all had plenty of hair and little in the way of surplus flesh. Listening to him talk about The Purdey, the abbreviated page-boy pertly held aloft on a wedge of expertly cut hair, which he created for Joanna Lumley in 1975 and which is threatening a mu-tated comeback, is quite a stretch.

But the conversation sounds decidedly anachronistic when it turns to Shirley MacLaine – who was so taken with him that she gave him a pot plant with a note saying “Every time I shake my hair I display your art” – or Brief Encounter (his favourite film “because Celia Johnson’s clothes remind me of how my mother dressed”).

His mother must have been very smart, I suggest. “Both my parents were,” he responds in his precise, faintly transatlantic clip. Frieda’s no slouch himself, what with the immaculate hair – no gelled cockatoo quiffs for him – and addiction to dark suits and handmade Charvet shirts.

Frieda Sr had started as a hairdresser, like his father, worked hard, moved into property, relocated to Harrow and sent his four children to private school. “He was horrified when I left school at 16 to be a hairdresser’s assistant.”

Not just any old assistant, though, but “the best towel folder and floor sweeper in the business”. And at Leonard’s too, a salon which, overspilling as it was with jet-setters such as Bianca, Mick and Twiggy, could not, at that time, have been more swinging. His father conceded that if one had to go into the trade, one might as well do it at Leonard’s.

I believe him about the towels. There is something militarily pristine about the way he dresses which, combined with a vague tinge of evangelism and the clean good looks that made him such a hit on US daytime TV, is rather potent. I bet Shirley was a little in love with him, like many of his clients were. Or as Lulu writes in I Don’t Want to Fight, her 2002 autobiography, “when he focuses on a person he gives them 100 per cent. He looks right into their eyes and they feel like the only person in the room.”

These days it is he who can impart knowledge. The staff at his four salons, two in London, one in New York and another in LA, tend to speak of him in tones otherwise reserved for gurus and Miuccia Prada. This may be because he motivates them with advice such as: “Don’t come in to work thinking of your mortgage problems or the row you had with your partner last night, just think of the next woman you’re about to see and how you’re going to give her the most amazing cut of her life. Which will make you feel really good about yourself.” Or perhaps they like working for what is generally considered to be the top hairdressing salon in town. Or maybe they just get spectacularly good tips.

He certainly credits meditation with helping him to succeed – although, half-Catholic, half-Jewish, he could make a case that his parents’ work ethic and a belief that “if a job’s worth doing . . .” exerted influence. Still, he says meditation helped him to think laterally and stay focused. By the end of the 1960s he’d discovered India and ashrams in a big way, although it took him almost two decades to master the art of meditation. A less committed disciple would have given up. John, Ringo et al, who visited some of the same ashrams, were dilettantes in comparison. “I was working around all these very successful people and a lot of them were unhappy,” he says of his motivation.

He wasn’t ecstatic himself. If Leonard’s hadn’t offered an early route out of school (which he hated, possibly because as a child he spent long stints in hospital), it’s debatable whether he’d have dedicated himself to hair in the first place. “Creatively, obviously hairdressing is very stimulating,” he sighs. “But intellectually it can be limiting.”

Lying on a beach, reading up on the Bhagavad Gita, Gurdjieff and Jung, in the early 1970s he contemplated “jacking it all in. But then I had an epiphany” (epiphany is a very John Frieda sort of word). The epiphany entailed opening his own salon. Then came The Purdey, which helped Joanna Lumley on her path to national treasure, was the saving grace of The New Avengers, the otherwise unglorious revival of the original Avengers, and was copied up and down the land.

Unlike hairdressers who license their names to off-the-shelf ranges, Frieda approached a chemist with specific requirements and in the late 1980s began packaging and labelling the products himself from the basement of one of his salons. Thickening was the next epiphany. He went on Richard and Judy’s This Morning to demonstrate its powers. “Suddenly the phones are going crazy and Judy’s twiddling her earpiece saying, will you stop jamming the lines.” Boots upped the order from a few thousand to more than a million.

The third epiphany was meeting Gail Federici, an American with phenomenal energy and marketing skills. Having sold his (and Lulu’s) home to finance the business, he moved to the US, crisscrossing the country to promote the products on countless local TV stations. The effort paid off. In 2002 he and Federici sold the product company for $450 million. The same year he met his second wife, Avery, an architect, having divorced Lulu in 1995. He then moved back to London, and had two more children.

He still works with KAO, the Japanese company that bought him out. The flow of new products is consistent, and consistently successful (the latest, a range of “glazes” that are applied after conditioner, thereby lengthening the hair-washing process by another step, caused an industry revolution, as did the Sheer Blonde, Brilliant Brunette and Radiant Red lines and, of course, Frizz Ease). It has been a very long time since he actually wielded a pair of scissors. These days it says “businessman” on his passport.

He’s definitely busy – there’s Europe to consolidate and the rest of the world to conquer – with his salons, cricket (another passion) and his young family. But beneath the calm of someone who has achieved everything that they set out to, he has the watchful air of a man who could do with another challenge.

A few years back he gave some money to the Conservative Party under Iain Duncan Smith’s leadership, a slightly false step for someone who’s so good on image, but he says now it was “more to get things moving than anything”.

The next time I see him it’s at a gala evening for the Lavender Trust, which he has co-sponsored. He grimaces, says he doesn’t really like these things, would much rather be at home, blah blah. It seems as good a moment as any to ask him about The Fountainhead (which is strangely gripping, by the way), but then Christy Turlington waltzes over, flings her arms round his neck and, whoops, he’s disappeared. Catchy stuff, fame.

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