A SUMMER night in 1993. Somewhere in the middle of Wyoming, three veteran cowboys are sitting round a blazing fire, remembering the good old days.' Ah, 1941, what a year]' says one. 'That's when they got rid of that crotch rivet on the 501 overalls. You know why? The boss of Levi Strauss was crouching over a campfire and darn near burnt his privates.'

'Never liked Levi's myself,' retorts the second guy. 'Best day of my life was when I bought my first pair of Wrangler jeans - the 11MWZ. They kinda gave a man that extra room he needs in the saddle.'

'Ah,' says the third, 'but nothing beats the Lee 101, the original cowboy pants. My pa bought a pair in 1924, Wore 'em all his life.'

That is how the three best-known American jeans brands would have us believe cowboys talk. A likely story. However, the brands do have impressive pedigree. And European jeans enthusiasts do love all the details: the names and numbers, the different cuts and washes, rivets, zips, pocket stitchings, beltloops, labels, the broken twill fabrics.

Levi Strauss, Lee and Wrangler are engaged in a fight to remind a world swamped with jeans brands that they were the originals. Ian Morris of Lee says: 'We're fed up with other brands taking styling details from our classics and claiming them as their own.'

Next month, Wrangler is reintroducing some of its most celebrated designs, including the 13MWZ, being promoted as the perfect 'cowboy cut' jeans (although collectors will know that it is an early Sixties variation on the 11MWZ, the first Wrangler jeans).

Wrangler is also bringing back its Original Slim Jacket (11MJ), first produced in 1948. The original buttons replace zips, and the jacket retains the vents on the backs of the shoulder seams designed to allow free movement for working cowboys. The company took the range to a Wyoming ranch, where the photographer Kurt Markus shot the garments on modern cowboys: a shrewd way of reinforcing the traditions of the brand (a limited-edition book is due out next month).

With this launch (or relaunch), Wrangler is taking its lead from Lee, which last year successfully brought out a collection of 'Lee Originals'. They included the loose-cut 1921 Loco jacket, tested with railroad workers, and the 101Z ring-spun jean, the first to boast a zip fly. Ian Morris's favourite is the Storm Rider jacket, first introduced 60 years ago, which has a corduroy collar and cuffs, and a blanket lining.

The move was astute. Suddenly, Lee were back in fashion, and streetwise retailers such as the Duffer of St George in London and Ichi Ni San in Glasgow are stocking Lee denimwear again. 'It's been good for us,' admits Morris. 'It's helped to reinforce the authenticity of our brand, our heritage, our workwear origins.'

Levi's heritage stretches back farthest. Levi Strauss designed the first jeans in the 1850s, for mineworkers, from unsold stock of brown duck and sailcloth used for tents and wagon covers. Roy Edmondson, the firm's marketing manager, believes the history is important. 'It gives the product integrity. We're not fashion, but above fashion.'

Levi 501 jeans, introduced in 1890, were relaunched in the mid-Eighties with notable success - probably the most effective relaunch of all. This year, the company has revived white corduroy and Bedford-cord jeans and slim-fit jackets from its Sixties back-catalogue. Mr Edmondson says the Levi archives hold an 'absolute multitude of stuff' that could be revived.

The denim companies are convinced that we, their customers, are impressed. Once we have cut through the hyperbole of the jeans marketing people, perhaps we really are.

The jeans story is mostly mythical (Wrangler began long after the heyday of the cowboy; Levi Strauss did not start calling its trousers 'jeans' until the Sixties), but the myth is powerful. For the fashion world's interest in all forms of workwear reflects the desire for a return to basics and, perhaps, to a time when life was a simpler business.

Great moments in jeans history

1855 Levi Strauss begins production of pantaloons from unsold stock of brown duck and sail cloth.

1860 Levi Strauss adds 9oz 'serge de Nmes' cloth, later known as denim, to range.

1873 Levi Strauss and Jacob Davis, a tailor from Nevada, patent a process of using metal rivets to reinforce overalls at stress points.

1890 Levi assigns lot numbers to its garments: the term 501 is used for the first time.

1905 Launch of the 506, the first Levi Strauss denim blouse (or jacket).

1911 Lee Mercantile Co produces its first line of workwear garments, including the Lee bib overall in 8oz denim.

1913 Lee launches the Union- All, a combination of jacket and pair of bib overalls. It is the US Army's official fatigue uniform during the First World War.

1921 Lee produces the Loco jacket for railroad workers.

1924 Lee launches the 101 Cowboy Pant, the first denim garment specifically for cowboys and rodeo riders.

1928 Lee adds a zip fastener to the Cowboy Pant, named the 101Z (Zipper).

Sanford L Cluett invents a system that reduces garment shrinkage to 1 per cent. The process is called Sanforization.

1933 Lee launches the Storm Rider jacket, with blanket lining and corduroy collar and cuffs.

1938 Levi Strauss introduces the tailored 701 Lady Levi's in a lighter-weight denim, the first jeans designed for women.

1947 Blue Bell Manufacturing company launches the 11MW, the first pair of Wrangler jeans.

1962 Levi Strauss launches the 557XX, also known as the Trucker jacket, with pointed pocket flaps.

Reference source: Cult: A Visual History of Jeanswear - American Originals, by William Gilchrist and Roberto Manzotti, published by Sportswear International, price pounds 62, from R D Franks, Kent House, Market Place, London W1.

(Photograph omitted)