Take a walk down any High Street or pop into any shopping mall and what will you find? A huge array of stores that sell, to the exclusion of almost everything else, one thing: fashion.

After the Second World War as Britain’s economy began to boom the consumer teenager was born. And by the mid-1960s there was a new innovative mecca devoted to this new young market.

Carnaby Street was once a scruffy, narrow backwater off London’s posh Regent Street. One man, an enterprising Scot, changed all that and helped make Carnaby Street famous the world over until, well, fashions changed.

It would be difficult to find a more unlikely candidate for fashion guru than John Stephen. He was born in Glasgow, the sixth of nine children, to a father who was an unemployed engineer until he opened a grocer’s shop. John left school at 15 with hardly any qualifications and became an apprentice welder on the Clyde.

He soon found that this was not the life for him. He was a sensitive lad who liked tidiness and order. After a stint in his father’s shop and at the Glasgow Co-op department store he decided, like many an ambitious Scotsman before him, to seek his fortune in London, taking up employment as a sales assistant in the gentleman’s dress hire company Moss Bros in Covent Garden. It was 1952 and he was just 18.

Stephen didn’t care for the stuffy hire shop and he moved to Vince, the first men’s boutique, just off Regent Street. Before he was famous, Sean Connery modelled a summer outfit for Vince’s 1957 catalogue. Twenty years later John Stephen would be a multimillionaire, with a flat in Mayfair, having bought his first Rolls Royce by the age of 20.

His apartment was in exclusive Jermyn Street, an address famous for its expensive, bespoke gentleman’s shirts. He also had holiday homes in Marbella and Cannes, and ate at the best restaurants with his constant companion Prince, a striking white German Shepherd dog.

Stephen, with only £300 of capital (much of it raised working nights in a coffee bar), opened his own men’s shop His Clothes in Beak Street, later moving to larger premises round the corner in Carnaby Street.

According to his biographer Jeremy Reed, ‘what Stephen had on his contemporaries, and to a degree shared with Mary Quant, was the ability to produce clothes faster and cheaper for a younger market’. He exploited new fabrics like Dacron and Acrilan and had local rag-trade workshops turn out limited runs, always keeping ahead of his demanding young clientele.

Stephen was the right man in the right place at the right time. He had business flair and was prepared to take risks. There was a self-destructive streak too; 17-hour days were not unusual.

Over the years dozens of bright new celebrities frequented John’s shops: Mick Jagger, Billy Fury, Georgie Fame, Barry Gibb of the Bee Gees, and members of bands like The Pretty Things, Small Faces and The Who.

In the early 1960s fashion was led by the scooter-riding Mods who (especially the boys) sought out cool, European-inspired garb and John Stephen – nicknamed “the Modfather” – was there to sell them just what they wanted. And what they wanted was colour (purple, acid yellow, pillar box red and apricot), hipster slacks, white polo necks, floral shirts and op-art ties...

Stephen himself always wore a timeless grey suit, a silk tie and an immaculate white shirt, a combination that never went out of date.

He continued to open more and more boutiques in Carnaby Street – Mod Male, Teen Store, His ’n’ Hers, and the Trouser Bar. The shops played loud pop, and looked like sets from the TV show The Avengers. Window displays were always daring and inventive.

His energy and determination were phenomenal but success took its toll. He’d struggled with bipolar disease for years and used alcohol to cope with his innate shyness. Cigarettes (at one time he smoked 50 a day) and Havana cigars were another indulgence. Perhaps he was all too aware that his fashion bubble would burst one day.

By the late 60s the hippies rejected manufactured style in favour of kaftans, braided military tunics, ex-army fatigue jackets, patchwork jeans and second-hand togs. All were a far cry from Stephen’s ever-changing colours and cuts.

Carnaby Street’s reputation faded. Pedestrianised in 1967, it became a tourist trap not a Mod mecca. Then in 1968, at the age of 34, John Stephen was diagnosed with a tumour in his neck. With the cancer in remission after painful radiotherapy he entered the new decade a changed man. Since Carnaby Street’s heyday, department stores had revamped their men’s floor to better reflect the new trends. The Carnaby era was over.

By the year 2000 he was still in the rag trade with an upmarket boutique in New Bond Street. But due to ill health (the cancer returned) he retired in 2002, dying two years later at the age of 69. Now on the wall at 1 Carnaby Street is a blue plaque bearing the legend.

Twitter: @KenWilson84

Info: The King of Carnaby Street: The Life of John Stephen by Jeremy Reed, Haus Publishing (2010)