No August Bank Holiday at the British seaside was ever complete without the wheeled armies of Mods and Rockers. A dubious tradition has ended, but the cult of Mod has endured, in pop music and fashion. Paolo Hewitt examines the origins of the species
To define Mod is not only impossible, it is totally at odds with its true nature. Mod is an insider's code, built on nuances, subtleties, attitude and style. Many have entered but few have cracked this code.

This most enduring of British youth cults is obsessive and perfectionist. It is working class, narcissistic and elitist. It demands instinctive good taste. No other fashion or lifestyle comes anywhere near its repeated success. The pleasure of dressing up to confront and confuse a world that tries to keep you down is eternal.

Mod's true birth day is unknown. Did it begin in 1955 when Frank Ifield announced to an uncomprehending press: "You can knock my talent but never ever knock my tailor"? Or was it when Cecil Gee, the clothes designer, took a summer vacation in Italy the same year and brought back van loads of brightly coloured jumpers? How about that famous picture of Miles Davis holding his trumpet to one side, dressed in an immaculate Brooks Brothers suit and scowling at the world? Or the West Indian citizens, with their shiny suits and extravagant hats? Were they the crucial moments?

Answer. All of the above, and more. Mod is a synthesis of black culture, its fashions and music, mixed with European colour. Mods were born the day the Second World War ended, but, to bring them fully to life, it took the resulting social upheaval: the abolition of National Service, the introduction of hire purchase, a perceived breakdown of the ruling class's morals, and a huge desire to build a brighter, younger world that would not repeat past mistakes.

In London, jazz clubs that catered for West Indians proved to be something of a catalyst. And then there was the young Sixties fashion mob - John Stephens, Cecil Gee, Anello and Davide - opening up clothes shops with eye-catching windows and music which cleared away a nation's cobwebs. As Sixties' chronicler Nik Cohn wrote, "clothes had become an adventure".

There was also a group called The Beatles about to explode, and, when they did, they kept talking about this label called Motown and this music called R&B. Naturally, the Mods knew all about R&B because it was perfect for their cause. It was underground and it was dangerous. It made its white equivalent, skiffle, sound tepid and risible.

At first, around 1961 or 1962, there were only a handful of stylists. They were far too cool to give themselves a generic name, but they were obsessed with clothes and a classless look. A young Marc Bolan was one. He was featured in a Town magazine article that was one of the first to bring news of this major upheaval in street life.

Unlike the Rockers, the smart suits worn by Mods did not signal overt rebellion. Instead, the rebellion was in their heads. They dressed bigger and better than their superiors, and the joke was, their superiors never even suspected what they were up to. Which was listening to black music and getting pilled out of their minds. They had discovered the delight, born out of a natural confidence, of dressing up and sending a signal out to the classes above them which said: You people may despise my accent but I am, and always will be, ten steps ahead of you.

Because of that, fashions changed weekly. Mods religiously watched Ready Steady Go! to pick up new ideas from the "faces" who strutted before the cameras. They spent hours in front of the mirror. From the way you wore your watch to the length of the vent at the back of your jacket, in Mod (we trust) it is always the small details that matter.

The original Mods sported the Perry Como Look, a very traditional, if slightly longer, version of the crooner's hairstyle. Later on, different style partings and bouffants came into play. Jackets became a minefield of detail concerning the size of the collar, sleeves and back vents. Shirts always had button-down collars, while trousers were slim and tapered, finishing off a good inch before the pointed or chiselled shoes began.

For a more casual look, desert boots (original Hush Puppies only), Levi's (mainly blue or white), Fred Perries or bright-coloured tops with a denim, suede or Harrington jacket affiliated Mod boys with the then-"exotic" continent of Europe. The Army parka was perfect protection against the cold as they roared about on their Italian Vespa or Lambretta scooters. For the girls, Mod was a disaster. Chunky cardigans, long, pleated skirts and drab blouses emphasised the early's scene's lack of sexuality. It would take Mary Quant to liberate them.

True Mod groups were thin on the ground. The Small Faces were authentic Mods who formed a band (as opposed to The Who, who had the image foisted on them), but their commercial success and huge appeal to screaming young girls effectively limited the boys' allegiance. The Action and The Creation were also genuine, but their inability to develop beyond one or two great singles consigned them to Mod cultdom.

Of course, it couldn't last. Mod swept the country, which was fine, but how can a mass movement remain elite? Mod became watered-down and hyped- up by the press. The energy that was once expended in making sure you looked just right was now used for press-inspired and ritualised bank holiday battles with Rockers. It was just all so... distasteful. Those who misunderstood were called "tickets". By 1967, it was all over.

But Mod never went away. It just surfaced in different guises. The skinhead, with his passion for correct clothing, was one such. So was the suedehead, the soulboy and the casual; as are the Acid House and Hip Hop nations.

In the Nineties, Mod has picked up again. The signs were already there in the late Eighties. London shops such as The Duffer of St George introduced a smarter look. A strange shoes- cum-antique shop in Chelsea called Patrick Cox started to approximate classic Sixties shoe design. Soon, all the major shops were stocking similar, mass-produced clobber. The football terraces - the true barometer, pre-Nick Hornby - of working-class fashion, had sported the look for years.

Pop music, dominated in the late Eighties by student Indie groups, sorely lacked style and arrogance. Enter the Stone Roses, Happy Mondays, Primal Scream and Oasis: all had grown up in the culture of Ecstasy, football and fashion, and saw little to inspire them. So, with rose-tinted glasses, they looked back to the Sixties, to a better time and a simpler world, when London was the cultural capital of the world, when pop belonged to the young, not the multi-nationals, and was brash and innovative.

Mod now is a direct reaction against the cheap Eighties. It's still impossible to define; and that, of course, makes it true Mod