Few artists have been more reclu-sive than William Roberts. When I began researching my book on vorticism in the early 1970s, he was still vigorously producing monumental paintings at his house near Primrose Hill in north-west London. As one of the few eyewitnesses surviving from the crucial pre-1914 period, Roberts could have provided me with invaluable memories of his fellow vorticists. But he always refused to see me or even answer my letters, and I soon realised that he treated everyone else with the same stubborn hostility. One journalist who was rash enough to ring Roberts's doorbell ended up kneeling on the front step, struggling in vain to conduct a conversation with the retiring artist through his letter box.
Now, in a very funny memoir written for the catalogue of a major Roberts retrospective, the curator Anne Goodchild recalls her bizarre encounter with him on a number 74 bus. Fascinated to gain a sighting of the octogenarian recluse, she followed him to the top deck. Aided by "the chutzpah of youthful inexperience", she respectfully asked him if she were addressing Mr William Roberts. After what felt like an interminable pause, and with his gaze defiantly averted, he replied: "I really do not know."
Roberts was so secretive that he would not even let his own son John into his studio. Decades ago, he turned down a request to stage a large exhibition of his work at the Hatton Gallery in Newcastle, where the present excellent show is being held. So he must have been his own worst enemy, obstructing the growth of his reputation by preventing the public from viewing the pictures he had produced with such commitment and care. The sad truth is that Roberts worked in a void for the latter part of his career, after the Arts Council mounted his retrospective at the Tate Gallery in 1965. From that year until his death in 1980, he hardly spoke to anyone except his devoted wife Sarah and John.
But by an extraordinary paradox, the paintings of his later years are largely devoted to celebrating the communal delights of London life. Far from focusing on isolated individuals, caught up in an obsessive protection of their own privacy, Roberts defined groups of gregarious, beefy figures shopping at street markets, feeding seagulls by the canal, chatting in the local pub and cheering at a football match. Like his French contemporary Fernand Leger, Roberts was an intensely social artist, determined to invest the most everyday scene with statuesque dignity and significance.
Among the late canvases displayed in the new exhibition, a tall painting called The Lake stands out. Probably based on a scene he knew well, at the Regent's Park boating lake near his home, it is dominated by the stiff verticality of massive foreground figures feeding the ducks or waving. We are aware of the overall flatness of the picture surface, and Roberts gave even the most distant boaters as much linear clarity as their largest counterparts on the water's edge. A commotion breaks out towards the top of the canvas, where angular arms stretch, bend and strain with almost as much geometric severity as the triangular sails floating beyond them. But the overall mood is genial.
The son of a Hackney carpenter, Roberts grew up in a working-class community. He began by drawing portraits of his immediate family, and the Newcastle show opens with some stern yet affectionate studies of his brother and sister. Their gazes seem watchful to the point of defensiveness, and Roberts must likewise have felt guarded when he entered the predominantly middle-class world of the Slade School of Art. Only 16, he was younger than most of his fellow students. But he found himself part of an exceptional Slade generation, including David Bomberg, Paul Nash, Stanley Spencer and the soon-to-be vorticist Edward Wadsworth.
Pre-war London was alive with intense, often virulent controversy about the invading European avant-garde. Roger Fry introduced post-impressionism and cubism in his two landmark exhibitions of 1910 and 1912. The futurists invaded the capital with their noisy, publicity-seeking belligerence. And Roberts was open-minded enough to respond, transforming mythological subjects such as The Return of Ulysses into stripped, angular images where the bodies already possess a suggestion of mechanistic stiffness.
Roberts was a brilliant draughtsman. His large 1914 drawing The Toe Dancer is a tour de force, showing the robot-like members of a bohemian artists' squat in Ormonde Terrace overlooking Primrose Hill. Here, presided over by a grizzled ex-lawyer called Stuart Gray, young artists including Bomberg, Epstein and Roberts worked in derelict studios and attended experimental performances by Gray's wife Marcia. Her outstretched body occupies the centre of the drawing, jutting and sinewy. But she also seems flattened, and the lines of the floorboards beneath her shoot up the picture with scant regard for perspective.
The loss of all Roberts's paintings from the crucial 1914-15 period means that we have to rely on his studies for these unknown canvases. Judging by an inflammatory study for Two-Step II, he became an audacious colourist. Blithely setting vehement orange against vivid puce, he painted machine-age dancers straining their girder-like limbs amid rigid forms redolent of an industrial city on the move. Everything has been purged of detail. Roberts was clearly among the most daring English artists of the period, and Wyndham Lewis wasted no time in rallying him to the vorticist cause.
When Blast exploded on to the London art scene in the summer of 1914, Roberts found himself catapulted into an intoxicating moment of rebellion. The Blast manifestos proved that English art had been revolutionised. A new, specifically 20th-century world of mechanistic energy erupted from the hard, clean structures defined in vorticist pictures.
But the seismic excitement did not last long. A year after Roberts took part in London's first and only vorticist exhibition in 1915, he was called up. The young man became a gunner in the Royal Field Artillery, witnessed scenes of appalling destruction and was finally rescued by official "war artist" commissions. Sadly, neither of his two large war paintings has made the journey to Newcastle. But some of his related drawings are here, and they provide a terse, urgent and chilling vision of the conflict. Some, such as Soldiers Hauling a Howitzer, show a hellish region inhabited only by forked trees, grim armaments and hunched, frowning men. In a subdued drawing called British Military Cemetery, Roberts portrayed bowed figures traumatised by the losses they are mourning as grey coffins are lowered into cold, geometric graves.
After the war, some of the former vorticists tried to revive the group camaraderie they had earlier enjoyed. But Wyndham Lewis's attempts to revive Blast failed in 1919. Too much had changed, including the constructive vision of the machine world. Now mechanistic power was associated with destruction, and Roberts developed a more flesh-and-blood figure style in his later work. He became disenchanted, and ended up grumpily maintaining that his early work had been cubist rather than vorticist.
All the same, a spirit of celebration lies behind Roberts's grand painting of the vorticists at the Restaurant de la Tour Eiffel in Percy Street, west London - one of the group's favourite hang-outs. Executed in the early 1960s, it places the moustachioed Lewis at the heart of a group gathering to toast the provocative arrival of Blast. Champagne is being passed round by the jerking, animated figures, and the boyish Roberts rests his hands on a copy of the heretical, pink-covered magazine. He looks more shy and detached than the other artists crowded around him, but the conviviality of this landmark occasion is caught persuasively enough.
England's traditional mistrust of modernity in art was being combated by these feisty, resolute insurgents, and Roberts was of the company.
"William Roberts: a retrospective" is at the Hatton Gallery, University of Newcastle (0191 222 6059) until 29 May, then at the Graves Art Gallery, Sheffield (0114 278 2600) from 12 June to 4 September