Gwen John and Augustus John
Tate Britain

Nicky Charlish

The title of this exhibition does more than inform us of its content. It tells us that it's presenting its subjects in a new light. We've been used to the John brother and sister act having only one script. There's Augustus, the gifted artist and archetypal lusty Chelsea boho, still trying to pick up young female art students in his dotage. And there's Gwen, the long-faced miserabilist, an artistic also-ran. This exhibition is an attempt to redress the balance - but does it work?

Born respectively in 1876 and 1878, Gwen and Augustus John were both students at the Slade School in London during the 1890s. From early on, there is an obvious difference in their approach to painting. Augustus's 'Ida Pregnant' of 1904 shows his wife looking at us, her expression a mixture of triumph, pleasure, disdain, almost dislike. By contrast, Gwen's 'Portrait of Dorelia' of 1903-04, shows their friend Dorelia McNeill radiating difference. But difference was far from the effect that McNeill would have on the lives of the artistic brother and sister - both would become infatuated with her, both projecting onto their different ideals or, perhaps obsessions. And those obsessions would lead brother and sister to follow diverging paths.

Augustus adopted a gypsy lifestyle, seeing it as representing a sense of community that modern society had lost. The outlook wasn't peculiar to him - this was the age of Arts and Crafts, garden cities and other variants on the 'back to the land' theme. It also, probably, fitted in with with his chaotic private life. - he had children with both Ida and Dorelia. His 'Wandering Sinnte' of 1908-1909 depicts a group of Piedmontese gypsies in an encampment showing a flowing huddledness reminiscent of El Greco, whilst his 'The Mumpers' of 1911-1913 shows a group of itinerant beggars with the colourful roundedness of Gauguin. His 'On Canford Heath' of circa 1913, has a sentimental, chocolate-boxy title. But Augustus gives us a windswept woman who, because of the vibrant reds, greens, and blues of her clothes, is almost crashing directly towards us out of the picture. But Augustus's enthusiasm for the simple life didn't rule out depicting the rising celebrities of the art world. His 'Wyndham Lewis' circa 1905, shows the future Vorticist, novelist and social commentator with a thick mop of black hair and a burgeoning sharp moustache that give him the air of a Mexican revolutionary about to summon a firing squad. 'Portrait of William Nicholson' of 1909 gives us a seated figure holding a cane who looks as if he's promenaded straight out of the pages of Proust, and who seems rather surprised that anyone should be bothering to depict him, even though he's a well-known artist and dandy.

Gwen John, meanwhile, adopted a slow-working, fastidious approach to her work. Living in Paris from 1904, she became a model for Auguste Rodin, eventually becoming his lover. Her work shows an almost monastic simplicity along with occasional flashes of optimism. 'A Corner of the Artist's Room in Paris (With Open Window)' of 1907-1909 shows a wicker chair next to a small table. Our gaze is led through the open window - through which light floods the room - to see flowering greenery and, beyond, pale blue sky. But her work generally has an understated depiction of low-level depression. Her 'Young Woman Holding a Black Cat' of circa the late 1910s-early 1920s shows a cat whose dishevelled fur you almost feel you can reach-out and touch being held protectively in the young woman's lap. 'Young Woman Wearing a Large Hat' from the same period shows a woman whose face is a mask of held-in worry, emphasised by the large semi-circular hat that is almost bearing-down upon her.

Gwen - who eventually became a Catholic - was asked by local nuns to paint Mere Poussepin, the 17th century founder of their order, using a devotional picture as a basis for her work. 'Portrait of Mere Poussepin' of the late 1910s, shows a figure who is meditative, unsurprised by anything and having a sense of assured wisdom. 'Young Nun (Portrait of a Nun)' of the same period is a deep contrast, showing a young figure beset with some mysterious anxiety.

Rodin died in 1917. Gwen's relationship with him hadn't been easy, and it's tempting to think that, whatever burden his death might have been, it was also the lifting of a wight from her shoulders. But her work continued to reflect melancholy. Her 'Seated Girl in Church' of circa 1920-25 shows us the back view of a girl whose head may be bowed in prayer or meditation but - just as possibly - in sadness. 'Girl With a Blue Scarf' of circa 1923-1924 gives us a figure whose face is tough, almost masculine, yet seems to be anxious about some unknown fear.

It's almost with relief that, after seeing the later work of Gwen - who died in 1939 - we catch-up with Augustus (who was to die 22 years later). By now he was painting establishment figures. His portrait 'Lady Ottoline Morrell' of 1919 shows the famous artistic and political patron black-hatted, heavily bejewelled and made-up and with a jutting jaw, as if Lady Bracknell has morphed into a drag queen. In contrast, 'The Hon. Montagu Collet, Lord Norman' of 1930-1931, shows this famous Governor of the Bank of England as if he were a sad-eyed bank manager about to foreclose on an old client.

But does the work of both Johns repay and deserve equal study? The answer is yes, although each artist's work took its own form. Their careers were helped - in both cases - by a lucky accident of birth. Had they worked say, a couple of decades later, their work and progress would have been mauled, marred and masked by Modernism. They both got their feet in the door of artistic noteworthiness just before it was slammed against their chosen styles. Gwen went for simplicity and remained with it. Augustus - after giftedly dabbling with Impressionism - adopted what we might call his bombastic official portrait style. Neither would have found favour with the artistic establishment. Perhaps what jointly gives their work its power is that they were both self-absorbed by their emotions to a degree that was unusual even for artists: the cataclysmic events of twentieth century history hardly impinge onto the work we're shown here; we are far from the trenches and dole queues. But that's precisely why their work would have come out fighting even if it had to contend with the fashions that dominated the arts from the Great War onwards. It's that power, that forcefulness, that shines through in this exhibition.

Till 9 January 2005