THE Queen Mother did not keep a diary, although it appears she had plenty of time to do so. At home, according to Hugo Vickers's informed biography, she made an art of doing nothing: reading, playing patience or simply relaxing on her chaise longue. If pushed, she might eat chocolates.

The result of this stress-free langour meant not only that she reached an extraordinary age, but also that her life must be told by others. What reality lurked behind this most consummate performer, one of the most loved figures of the last century?

Cecil Beaton captured her as well with words as he did with his camera. "It was an ugly dress & very dowdy, & her shoes were too elaborate, & her jewellery was messy . . . but does it matter what she wears, for her charm so overwhelming?" he wrote of the Queen during the Second World War.

She was, he said, "a marshmallow made on a welding machine". Her voice, he said, "is like a sad child's voice, infinitely moving. She held her head on one side, looked very wistful and yet managed the interview in quite a businesslike way."

Norman Hartnell, her dress designer, said the colours of her clothing - dusty pinks, blues and lilacs - was deliberate. "She wished to convey the most comforting, encouraging and sympathetic note possible."

And author Enid Bagnold remembered: "She has extraordinary control of every facial muscle, so that she makes valuable every look and half smile, every tilt of the head, in a very expressive way."

An accomplished actress then: a tiny, pastel powderpuff of a woman; sugary; and if not false, then someone who almost did not exist unless she was on show.

We know by now - indeed, we have rehearsed for what feels like a century - the story of Elizabeth Bowes-Lyon, the baby of a large Scottish aristocratic family, born into a castle full of "rotting tapestries and hideous Danish furniture", as Stephen Tennant described Glamis.

Hugo Vickers's work is deceptive. A lifelong monarchist, he starts this biography as panegyric. Too many things are delightful, or enchanting, about the sporting Bowes-Lyons "who followed the birds" from mansion to mansion and who produced a child "unique in the twentieth century in never having had to draw her own bedroom curtains."

But readers should persist, for Vickers, in his arch, courtly way, proceeds wickedly in the second half of the book to reveal a woman who, according to Tennant, "schemed and vacillated, hard as nails."

Queen Elizabeth picked her men, Beaton said, with the skill of a chess player. She was a fixer. Her brother David, known as a man of "extreme right-wing views and a baleful inf luence at court" was married but was primarily (and, it appears, rampantly) homosexual. After the war, the king and queen tried to get him the job as governor of New South Wales, but were thwarted.

Later, when her niece, Anne (mother of the late Lord Lichfield) , found a husband from the lower ranks of the Danish royals, the Queen Mother wangled her the title HH Princess George of Denmark. Status mattered. Things were of their place and class. Mrs Roosevelt found her "a little too self-consciously regal".

The right kind of publicity mattered, too. The Queen, who entered the hearts of war-torn Britain for her refusal to leave London, complained about the lack of press coverage of the King's activities in 1943, resenting the way his troop visits were either ignored or placed in what she called the "snippets columns". She suggested a tame press man might be employed.

No Bowes-Lyon, it was said, cared for things of the mind, and the Queen was criticised by her motherin-law, Queen Mary, for her lax attitude towards educating the two princesses. She did little about it. Worrying was not Elizabeth's style. At times of trouble, she "ostriched". During the crisis over Margaret's marriage to Townsend, she refused to offer advice. The unhappy Margaret threw a book at her mother's head.

Beaton said of the Queen Mother: "She came in fresh & fat & leisurely, exuding serenity". He also, in cognisance of her sexuality, recounted this verdict from a taxi driver in the Bronx: "There's many a man would like to marry her, with her smile and bright eyes, and she'd be a pleasing handful at playtime."

Slyly, Vickers inserts irreverence like this alongside a sustained tone of snobbery. In the footnotes he lectures, patronisingly, on her titles. "A distinction could be made whereby the cognoscenti used Queen Elizabeth rather than the Queen Mother."

After the king's death, Vickers says that she minded greatly the loss of her power base. The 51-yearold widow's skill "was to create a new role" - mostly enjoying herself, but also bolstering the whole reputation of the Royal family.

She was a joyous person, and she was unimpeachable, but we must question how well we knew her. Helen Hanff, the American author of 84 Charing Cross Road, remarked: "Her public image is a masterpiece of press agentry. She has the coldest eyes I have ever looked into."

She also had gloriously right-wing views. She hated Germans, and when Crown Prince Naruhito came to visit, she insisted the Japanese sword of surrender be put on display. The Queen vetoed this. As they processed into dinner, the Queen Mother said: "Come on everybody, nip on, nip on!"

Vickers really comes into his own describing the life of the dowager queen at Clarence House, run as a vast Edwardian court of private secretaries, equerries, ladies-in-waiting and uniformed staff.

Courtiers dined in style every day; then they took tea; then "a certain amount of alcohol was served at the appropriate hour". Lt-col Martin Gilliat, her bachelor private secretary - "as generous in dispensing his own alcohol as he was in pouring Queen Elizabeth's" - cut out pages from books if he thought they might offend her. Sir Ralph Anstruther, beset with rumours about the young men in his life, oversaw finances, though he "had but a hazy idea of costs".

And then, of course, there were ladies in waiting: Lady Fermoy and Countess Spencer, fatefully grandmothers of Diana Spencer. (Vickers sometimes sounds like a lady-in-waiting himself, with judgmental remarks about Diana "openly disporting herself with Dodi.") The Queen Mother was sent into decline by the Diana/Camilla saga, but we should remember her as Vickers portrays her best: a tough, dedicated matriarch from another age, someone who gave huge happiness to her subjects, but who was also a simple creature, one who liked uproarious dinner parties, refused to visit dying friends, collected fine art and ate a little too much.

It will be interesting to see if William Shawcross, who is writing the official biography, can do better.

Elizabeth, the Queen Mother, Hugo Vickers, Arrow Books, pounds-20.