How did a set of pre-WW1 painters in Camden shape our modern vision of London?

The Camden Town Group of painters disbanded after only 18 months, but their work shapes our vision of London to this day. Michael Glover looks forward to seeing their reunion

Next month, Tate Britain will be putting on a major show devoted to the work of the Camden Town painters, a London-based group, formed in 1911, which helped to redefine the nature of modern British art just three years before the outbreak of the First World War.

These artists - there was a core group that comprised Spencer Gore, Charles Ginner, Robert Bevan and Walter Sickert, and another dozen or so more loosely connected - came to be known as the Camden Town Group because a number of its members lived in the area. The Tate itself owns the largest collection of Camden Town Group paintings in existence, many bequeathed by relatives or private collectors.

The group stood for modernity of a kind - it had absorbed the lessons of the latest wave of inventiveness sweeping over from France called post-Impressionism - but it was also founded on pragmatism. These painters were finding it hard to sell their works, and if they defined themselves as a group, they knew they would have more clout. So, in 1911, a small group of not-so-young, male painters met at Gatti's Restaurant to try to define a new kind of art.

Camden, having once been grand (it's grand all over again these days), had become shabby, if not seedy, and that's why such painters as Sickert, who gave the group its name, and was its chief propagandist and most prominent member, liked it. The group didn't last for long - they had just three exhibitions over a period of about a year and a half - but the kinds of work that developed out of their collective endeavours continues to be a defining moment in the history of British art in the 20th century, and it has had a major impact on the art of our own day. Without the Camden Town Group, without the way they depicted the human figure, without their bravura use of colour, and how they helped to define the nature of London's architecture and London's life, often eked out in shabby rooms, Lucian Freud, Frank Auerbach and Leon Kossoff might not be painting the texture of London, and the human figure too, quite in the way that they are still doing.

It was a movement that, looked at superficially, seems to be scarcely radical at all when compared with many of the 20th century's more famous artistic alliances - there is no wild distortion of the human figure here, and no extreme experiments in abstraction. Leave that to the Vorticists, who would follow so close on their heels. Instead, there were much more subtle absorptions of lessons in patterning, abstraction, unusual viewpoints, and non-realistic use of colour. There is much that is genuinely radical here, but it is often expressed in quite a sotto voce, hole-in-corner kind of a way. Most of all, there is the starkly absorbing subject matter of much of the art itself - human life, in the raw, in the greatest of the world's metropolises. This was egalitarian art for an egalitarian century.

The texture of London is what is at the core of much of the art of the Camden Town Group. London was a mighty, teeming metropolis then - as it is now. It was also a tense city, fearful of the threat of a German invasion. It was a maze-like place, full of corners, small alleys, and Dickensian character types. There was an ugliness about all this, certainly, but, within that ugliness, a certain kind of awkward beauty.

To the Camden Town Group, a relatively prosperous bunch of middle-class males, the coloratura of the streets was ravishing. You could hear the indomitable coster-girls, tricked out in their brilliantly colourful hats, bawling out, trying to persuade you to buy their wares. You could see the men teeming and lurching out of the pubs. And there were the charwomen, the cabbies, the cheering audiences in the cheap seats at the Alhambra Music Hall. This London had nothing to do with the fashionable society portraiture that John Singer Sargent had made so much his own. The Camden Town's London was homespun, down to earth, tackily real.

Sickert saw London's beauty in something different from the fashionable world of dutiful retainers and immaculate coiffure, as he wrote himself. "For those who live in the most wonderful and complex city in the world, the most fruitful course of study lies in a persistent effort to render the magic and the poetry they daily see around them."

Sickert was part Danish and part English by birth, and had come back to London in 1905 having spent much of the previous decade on the Continent. He'd learnt to be an Impressionist over there. He'd painted the melancholy of Venice, all that drowning, flickering glitter. He had also become a close friend of Edgar Degas during those years. Degas taught Sickert a lot about how to paint a nude body in the raw.

Now it was time for something new in England - but this would also incorporate what he had learnt over in France. Sickert bedded himself down in Camden Town, and began to paint what he saw: brutish modern life, in the raw; short, harsh and unflinchingly ignoble. Alienated modern life, if you prefer a more intellectualised handle. This was the kind of thing that Baudelaire had felt on his pulses in 19th-century Paris. It was also the kind of vision of urban life that seems to lead directly to the kitchen sink drama of the 1950s.

In the later 19th century, painters had been stymied by the need to be either sentimental or moralistic. The Church and the state seemed to have them in a tight squeeze. Sickert shrugged them off. Consequently, what he did was an out-and-out scandal. Being a self-confident and wily self-propagandist, Sickert revelled in their condemnation of his subject matter - and of his unorthodox painterly habits.

When we look at Sickert's paintings of big women - so much marketable flesh - sprawled across iron bedsteads in murkily lit rented rooms, often loomed over by square-jawed, fully dressed men of incalculable insensitivity and pent-up violence, with a brassy chamber pot naughtily peeking out from beneath the bed, we wonder whether this could be the same Edwardian London that Merchant-Ivory sees through its misted lenses. And yet Sickert loved all this, as he once told us. "London is spiffing!" he wrote. "Such evil racy faces & such a comfortable feeling of a solid basis of beef & beer. O the whiff of leather & stout from the swing doors of the pubs! Why aren't I a Keats to sing them?"

Yet there was more to the Camden Town Group than Sickert alone, and what is so pleasing about the show at the Tate are the discoveries. Among the most exciting is a painting by Spencer Gore, on loan from a private collector, of a group of connoisseurs admiring the exhibition of Post-Impressionist art from France that Roger Fry had brought to London in 1910, and which had caused such an outpouring of bemusement and critical venom.

Gauguin and Connoisseurs (1911) is a delightful exercise in pastiche. The paintings on display are all recognisable works by Gauguin, and their critical scrutineers are plainly recognisable too. Here is Philip Wilson Steer, for example, solidly old-guard, with his walking cane and grey gloves, distancing himself physically from the shock of the new; and here is a red-bearded Augustus John looking in the opposite direction with ferocious disdain. The way it is painted, including the muted, synthetic colours, perfectly matches Gauguin's own palette and manner of painting.

The Post-Impressionists were evidently here to stay, but now it was an Englishman, born in Epsom, Surrey, who was wielding the brush.

Modern Painters: The Camden Town Group opens at Tate Britain, London SW1 on 13 February. Tate Britain is offering Independent readers the chance to book two tickets for the price of one before the exhibition opens. Simply call 020-7887 8888 and quote 'Independent two-for-one offer'