Queening it

The front cover of this double biography shows Mrs Keppel, mistress of Edward VII, creamy in lace and lilacs, holding to her breast and gaze a soft-fleshed sprite of about four: her daughter Violet, whose silk smock is lifted and folded back to show not only her flexed, round knees but her lace-edged knickers. The mother, her head a heavy wheaten coil, her lips parted, looks like a girl. The child, a bow in her - the word is unruly - curls, looks like a wary woman, reading incessantly the eyes of the adored and radiant other. On Alice Keppel's hands rests the tense, artificially posed, index finger of Violet's right hand.

According to Harold Nicolson, the husband of her most celebrated lover Vita Sackville-West, Violet Keppel, later Trefusis, was like "some fierce orchid, glimmering and stinking in the recesses of life". Diana Souhami declares her agenda early on in this double portrait (incidentally her third attempt at the genre). She is out to correct the widely received version of the story as told in Nigel Nicolson's Portrait of a Marriage, which, quite naturally, was more tender to his parents' marriage than to its catastrophic interrupter. Souhami is also keen on the ironies of sexual morality inherent in her material: was Mrs Keppel's behaviour really so much more acceptable than that of her more obviously outrageous daughter?

Convention in the conduct of sexual relations reached its duplicitous height under Mrs Keppel's fat old lover. Diana Souhami sees the potential in her subject for drawing pompous sociological conclusions and, on the whole, resists them. The best parts of her book are those where no moral is drawn and where we see the drama of love, not between the King and his mistress, nor the many grand lesbians who throng its pages, but between a mother and daughter increasingly similar in decline, arriving, after appalling disaffection, at a final, mutual, doting.

Violet Trefusis is already familiar as an irritating presence in the biographies of many of her contemporaries: over-made-up, drunk and preposterous, purveying the tired canard that she was the King's daughter, pretending that she was engaged to a string of down-at-heel, invert not-quite-noblemen, cavorting among her bad antiques and generally doing anything for attention. Nancy Mitford famously suggested the title of her autobiography should have been "Here Lies Madame Trefusis". Her novels are for the most part scented wastage. Yet she had a speed of intuition and a gift of summoning mood and sensation in words - most evident in her exhausting but spangled correspondence - that make one regret her desertion of her own best self, the victory in her of the gimcrack over the fierce and intelligent, that might really have made something of her bizarre lonely childhood and voracious dedication to love. She said of herself "Across my life only one word will be written: 'waste' - waste of love, waste of talent, waste of enterprise." Yet she was better read and more privately subtle than her detractors allowed. It is possible that, unlike those among that galere whose reputations have weathered better, she never found a convincing outer persona to inhabit.

Only money looms larger in this book than the personality of Violet Trefusis. Souhami conjures the cluster and glut of the times, and their weighted precariousness. Her accounts of Mrs Keppel's fluster over cash at the death of her protector, and the dealings of Sir Ernest Cassel, "the King's millionaire", are mirrored by her retelling of the lawsuit involving Vita Sackville-West's own terrifying mother and her vastly richer admirer, Sir John Murray Scott, known as "Seery". As Diana Souhami says, Violet and Vita "were used to the presence of immensely rich, genial, fat men who adored their mothers and turned their fathers into shadowy figures".

"Mama," asked the child Violet, "Why do we call Grandpapa Majesty?" The Keppels' life was a grand progress in the wake of the King, discreet-ish except for the spring break in Biarritz, where for the season Mrs Keppel became queen, off England. When, in spring 1908, Campbell-Bannerman resigned and Asquith was elected, the King and Mrs Keppel were in Biarritz. The King refused to interrupt his holiday in order for the new Prime Minister to kiss hands, so Asquith joined them. After the ceremony, he wrote to Mrs Keppel:

"Before leaving Biarritz I must send you a line of most sincere thanks for your kind words and wise counsels, which I shall treasure and (I hope) profit by.

"It was a real pleasure to see you at such a time, and to be made to feel that, whatever betides, I can count on your friendship."

Translated into our own time's equivalent personnel, this is an extraordinary document.

Violet wrote to Vita: "We are not as loveable, or as good looking, or as successful as our mothers." Edward VII, too, was defined by the sense that he was an inadequate successor to a parent: the Prince Consort. His riposte was never to grow up nor control his infantile appetite for adult pleasures. The sequence of heredity does not stop with the story this book tells, as its later chapters sketch in, with here and there a blush of stylistic vulgarity. Camilla Parker-Bowles is the granddaughter of Violet's sister Sonya. Souhami treats of this without too much fuss, according, rather, attention to the antecedents that have surely made Mrs Parker-Bowles far from the straightforward horse of caricature. She may be exactly the person for the job.

Violet Trefusis, who bore until she died the name of the man she never loved but married with society's blessing, ended her life an insomniac - "I am sleep's beggar, grateful for a yawn" - confronted in the small hours by the word "declasse" standing against her "like a gamekeeper". She tyrannised her maid Alice. She allowed possessions to conquer her. She inserted "femme de lettres" against her name in the telephone directory. She liked to claim that she was thirtieth in succession to the throne. There were excruciating visits to and from Vita. Harold Acton said, "one can almost hear Violet remarking like Lady Montdore [in Nancy Mitford's Love in a Cold Climate]: 'I think I may say we put India on the map. Hardly any of one's friends in England had even heard of India before we went there you know.' "

Diana Souhami astutely suggests that Violet was "always her mother's understudy ... but the performance was caricature. She was too intelligent, too caustic and disappointed for it to be otherwise. The true spirit of Edwardian hypocrisy eluded her." For such well-turned imaginative insights, Souhami can be forgiven the repetitions and occasionally insistent tone that sometimes mar her book. She has a sharp eye for the grotesque: the Nicolson nanny being sacked for mimicking Vita in a suit of Harold Nicolson's; the untrustworthy lesbian flirt Pat Dansey's writing-paper stamped with her seal - a witch astride with the motto "All Have Their Hobbies"; Mrs Keppel giving her daughter for her wedding "A diamond tiara, an emerald and diamond pendant, an 18th-century diamond brooch in the shape of a sheaf of wheat and Nannie." Souhami's book goes a long way towards restoring to Violet Trefusis some of the dignity that all her own worst efforts could not quite efface.