Life after Osbert, Edith and Sachie: Vicky Ward spoke to the sons of Sacheverell 'Sachie' Sitwell about growing up in one of the oddest families in 20th-century art

Sir Reresby Sitwell, 67, and his younger brother Francis, 59, are distinctly uneasy in each other's company. To publicise 'The Sitwells' - an exhibition looking at the remarkable lives of their artistic ancestors, which opened last week at the National Portrait Gallery in London - they request that they be interviewed separately. At the private view, I overhear a guest talking about a family feud; meanwhile, one of Francis's sons, William, mentions he has only ever visited Renishaw, Reresby's home, once. 'We aren't particularly close,' Sir Reresby later acknowledges, 'but we are eight years apart in age.'

If the friction is really tremendously bad, however, the pair are not letting on. They agreed to pose together for a photograph, and they do, in fact, end up talking to me together for a brief while.

Reresby and Francis are the only sons of Sacheverell (more commonly known as Sachie) Sitwell who, together with his siblings Edith and Osbert, took the artistic establishment of the 1920s and 1930s by storm. Poets, writers and musicians, they fought vigorously against all that was uncultured - what they called 'the Philistine' - and had a love-hate relationship with the new-fangled ideas of the Bloomsbury group.

The Sitwells quickly became the celebrities of the literary establishment; the exotically dressed Edith was photographed endlessly in controversial poses - the most famous is of her stretched out in a coffin - by Cecil Beaton, while Osbert concentrated on novel- writing and Sachie wrote about archaeology and art. Their fame reached its zenith with Facade, the performance of Edith's poems set to music by Sachie's young protege, William Walton. The work was ridiculed at first, but later acclaimed as highly innovative.

After 1925, when Sachie, oppressed by living with Osbert (a homosexual), married the beautiful Canadian Georgia Doble, the trio went their separate ways, to Osbert's initial fury and Edith's consternation. But Edith, in particular, went on to win sufficient acclaim as a poet to earn her a damehood, and Osbert's five-volume autobiography, Left Hand, Right Hand], became a staple on many school reading lists.

Their friends, who included Gertrude Stein, Diaghihev, Rex Whistler, T S Eliot, Virginia Woolf and Wyndham Lewis, all looked upon them as different and eccentric, in D H Lawrence's words, 'as if they had been brought up on a desert island' - and in many ways they had.

Their childhood at Renishaw, a gloomy, ghost-ridden Jacobean mansion among the coal mines of Derbyshire (the setting for Lawrence's Lady Chatterley's Lover) was unhappy. Their father, Sir George Sitwell, was an eccentric who locked himself away in his library studying bizarre topics and insisted on eating alone. He saw sex as purely functional. Before committing the act he would go on a strict diet and read some scholastic work before announcing to his wife, 'Ida, I am ready.'

Their mother, Lady Ida, was a society beauty who had no interest in her husband's intellectual pursuits. She spent all day reading in bed or playing bridge - and eventually brought disgrace upon the family in 1915, when her gambling debts led indirectly to a jail sentence for fraud.

It is hard to reconcile the two rather short, tubby jovial gentleman in front of me, every inch the English country squires, with their exotic, unusually tall - Sachie was 6ft 5in - anarchic, eccentric, artistic forebears. On the other hand, of the three siblings, Sachie was considered the most 'normal': he was the only one who even married.

I ask Sachie's sons for corroboration. To my surprise they shake their heads. 'Perhaps he was more normal but I'm not sure about happier. He was a far more complex man than that,' they both say. 'There was a dark side to his nature,' adds Reresby, 'I was terrified of him.

'I remember that my school report would arrive on the same day as Country Life and that he would read the report in one hand and bash me over the head with the magazine in the other,' says Reresby. Francis's face lights up.

'You too?' he asks, 'I used to intercept mine before it got to him.'

Reresby, the talker of the two, goes on to narrate how he once filled a questionnaire at his prep school, Sandroyd. ' 'Why did your parents send you here?' it said. I answered,' he chuckles. ' 'Presumably because they recognised a fellow sadist in the headmaster.' '

I ask them about their parents' famous life-long infidelities. 'It was very distressing,' says Francis, and Reresby nods in agreement. 'And it became more distressing the older we got. Our illusions were shattered.'

The conversation turns to Eton, and for the first time I think I detect a chip off the old block: 'We certainly did not enjoy it - because it was very sporty,' says Reresby, 'and we loathed games.' At this point, in characteristically jovial fashion, Reresby trundles over to the door to show me how his housemaster - a sports fanatic apparently - had been able to raise his legs up to the ceiling.

Despite his professed dislike of the school, however, it turns out that Reresby actually did rather well academically (more than could be said for his father, uncle or indeed brother). 'You won the school essay prize,' Francis reminds him 'and got a scholarship to Cambridge.'

Neither event seem to hold much value for Reresby, however. I ask him if, in view of his ancestry, he had ever tried to write. 'Oh no,' is the abrupt answer. 'You see I'm rather shy of writing.'

A Sitwell? Shy of writing? 'You have to understand,' says Reresby quickly, 'that our father wrote so many books - 137 in total.' Have you read them all? I ask. 'Good Lord, no,' they reply together.

At this point Francis suggests he leave me with Reresby for half an hour - I have sensed throughout that he feels uncomfortable, perhaps stifled by Reresby's presence. Reresby on the other hand is confident and chatty. He talks easily about his upbringing at Weston Hall, Northamptonshire, (Sachie's marital home, where Francis and his family now live); his various careers, which ranged from salesman at Fortnum & Mason to wine merchant. He sweeps over his marriage to an aristocrat, Penelope Forbes, which caused huge friction with Sachie and Georgia. 'They were an arrogant and nasty,' says Penelope later, when I visit their home, Renishaw. 'She was jealous of me because I was better born.'

What is clearly Reresby's pride and joy, however, is Renishaw, bequeathed directly to him by Osbert (Sachie had opted out on account of death duties).

'Osbert left me the house in 1965 when he went to live at the family's Italian home, the Castello di Montegufoni,' he says, 'but he did not leave any money.' Slowly, he and Penelope, whose talents as a gardener, musician and gilder he eulogises throughout the interview, sought to exorcise the place and create a genial family home for their daughter, Alexandra. He is especially proud of the beautiful gardens, which are now open to the public.

Judging by the way he talks, smiles and jokes, Reresby is a happy individual, untainted by memories of the past and living wholly for the present. 'I think Peneople and I have led rather happier lives than my ancestors,' he smiles. Later he shows me a private letter from the historian Philip Zeigler: 'Gloomy and sinister seem to be the adjectives most often applied to the house under the last generation; but whatever there was to give it that reputation seems to have been completely exorcised.'

Francis reappears and I notice now that he hangs his head in his brother's company and lifts it when he is gone. He speaks more slowly than his brother, as if he is thinking very carefully - but then he has worked in PR for most of his life, and perhaps is more wary of journalists. It is clear that Francis feels more oppressed by the family history than Reresby. 'I was too young to be given a choice so I was sent away to Canada during the war,' he says 'which was a mistake because I was behind academically when I returned and only scraped into Eton where I was teased because of my Canadian accent.

'I did, however,' he says, almost with defiance, 'pursue the things I enjoyed. I became secretary of the Natural History Society and got involved with music which was just getting going there.'

And, of the two, it seems that it is Francis who has continued to fly something of the family's cultural flag. He is a founding member then chairman of the music charity, the Park Lane Group - which organised Edith's 75th birthday concert at the Festival Hall in 1962 - an occasion which moved her to tears; he was on the councils of the London Philharmonic Orchestra and the Byam Shaw School of Art and this week attends his first meeting of the board of Sadler's Wells.

Significantly, Francis did not choose a career directly in the arts. 'My business career (at first with Shell Petroleum and, since 1966, in financial PR) gave me independence,' he says, adding softly. 'It gave me the means to get away from the family.'

I ask him if he thinks his father would have minded that he had not pursued an artistic career. 'No, I don't think so,' he says. 'I think both Reresby and I have a far better life; my father was not a happy man; he was very disillusioned; he was always in his brother's shadow and he had no religion to fall back on. He was haunted by the fear of getting old.'

At the same time, Francis seems fiercely proud of his family. 'Perhaps my forebears have suffered exclusion but if they, or anyone else, had any doubts about their achievements then the proof of the pudding lies in this exhibition, which has taken the gallery three years to put together.'

Francis made many devoted trips to Edith's house during her bedridden last years - to the end she dressed as bizarrely and entertained as vigorously as ever. 'If they had been alive to see last night's private view,' he flashes, 'they would have been the proudest people in the room.'

(Photographs omitted)