The hidden past at Windsor: All families have secrets, and the Royal Family is no exception. But they can lock theirs up for ever in the archives. In matters of public interest, that's a big mistake, Richard Tomlinson argues

The past is another country, whose frontier is patrolled by Victoria's descendants.

Now, about the letters which you wrote to me the other day, Victoria replied to her eldest daughter, the Crown Princess of Prussia, in March 1874. I am not for burning them except any of a nature to affect any of the family painfully . . . I am much against destroying important letters, as I every day see the necessity of reference.

But before she died in 1901, Victoria instructed her youngest daughter Beatrice to rewrite the journal the Queen had kept almost daily since adolescence, deleting similarly painful passages. The original was to be destroyed. For 30 years, Beatrice laboured at her task, burning each volume of the journal as she proceeded. Although the sanitised version ran to 111 volumes, it is a fraction of what once existed.

Where Beatrice literally blazed a trail, other courtiers followed. Lord Knollys, Private Secretary to Edward VII (1901-10), obeyed Queen Alexandras wishes and destroyed virtually all the late King's personal papers. His younger sister Charlotte performed the same service for Alexandra when she died in 1925. For several days, the smoke could be seen billowing from the chimneys of Sandringham House, where Alexandra had lived in widowhood.

What the Royal Family did not destroy, it lodged in the royal archives at Windsor, established shortly after Victoria's death. Here are stored the remaining papers of Victoria and Edward VII, as well as those of George V (1910-36), Edward VIII (1936) and George VI (1936-52). When the present Queen dies, her papers will also be transferred to the collection.

Access to the royal archives, which are the private property of the sovereign, is necessarily restricted, writes the registrar Sheila de Bellaigue, for the privacy of the Royal Family, whose papers are preserved there, must be respected.

All families have secrets, and the Windsors are no exception. Buried in the archives, for instance, there may be more to discover about Prince John, George V's youngest son, a mentally retarded epileptic who was removed at an early age to a farm on the Sandringham estate, and died in 1919 at the age of 13.

An argument can be made that such private tragedies are nobody else's business. The difficulty with the argument is that the Royal Family also has a public identity. By controlling access to the archives, it has sought not merely to bury its secrets, but establish an authorised (some would say laundered) history of the dynasty.

The chosen medium is official royal biographers, the only scholars to have been granted unrestricted access to the archives. Other researchers may approach the archives for information not contained in the official biographies. In the absence of a published catalogue this is uphill work, especially given the stress still placed on privacy.

From the family's point of view, the official biographies have proved an unsatisfactory means to a dubious end.

Harold Nicolson's biography of George V, begun in 1948, is a case in point. It is not meant to be an ordinary biography, his friend Sir Alan Tommy Lascelles, Private Secretary to George VI, told Nicolson. It is something quite different. You will be writing a book about a very ancient national institution, and you need not descend to personalities. Lascelles added that Nicolson must omit things and incidents which were discreditable. I could say this in the preface if it would ease my mind.

In private, Nicolson had mixed feelings about his subject. I fear I am getting a down on George V just now, he wrote to his wife in August 1949. He is all right as a gay young midshipman. He may be all right as a wise old King. But the intervening period when he was Duke of York, just shooting at Sandringham, is hard to manage or swallow. For 17 years (1893-1910) he did nothing at all but kill animals and stick in stamps.

In Nicolsons biography, the same period is described rather differently. For him, Sandringham, and the Sandringham ways of life, represented the ideal of human felicity . . . It was here that, after 15 yearsabsorption in the mysteries of the sea, he came to learn and love the mysteries of the soil.

For his gifts of circumlocution, Nicolson was rewarded with a knighthood. He was snobbishly ungrateful, having hoped for a peerage. After all the work I have done in life, a knighthood is a pitiful business, putting me in the third eleven, he complained in his diary.

There comes a point when the private behaviour of royalty is a legitimate matter of public interest. Edward VIII's affair with Mrs Simpson remains the most unequivocal example this century. Yet no royal crisis has been shrouded in so much secrecy. Until little more than a week before his abdication in December 1936, the British people had no knowledge of the King's affair, even though it was front-page news in Europe and the United States.

The Duke of Windsor (as he became) did eventually put his side of the story in a ghosted and thoroughly unreliable autobiography, A King's Story (1951). Lascelles, according to Harold Nicolson, was very distressed about the book. The Duke's younger brother, George VI, was appalled.

Faced with the Duke's indiscretion, the instinct of the rest of the Royal Family has been to close ranks. Leading the way is George VI's formidable widow, the present Queen Mother, referred to by the Duke but not in his memoirs the ice-veined bitch.

Her hand can be detected, for instance, in a box of papers belonging to the former minister and royal confidant Lord Templewood (Sir Samuel Hoare), now stored in the Cambridge University library. The box is described as correspondence with George VI, Queen Elizabeth and the Duke of Windsor and memos 1925-58. It may contain material relating not only to the abdication crisis, but also the Duke's possible involvement in 1940 in a Nazi plot to restore him to the throne.

A note in the catalogue explains that this file may not be seen without the permission of the Royal Librarian. A line has been crossed through part of this instruction, so the message now simply reads, This file may not be seen.

As it struggles to address the future, the British dynasty appears unable to come to terms with its past. I sometimes wonder how future generations will judge the events of this tumultuous year, the Queen remarked in November 1992 of her annus horribilis.

I dare say that history will take a slightly more moderate view than that of some contemporary commentators. Distance is well-known to lend enchantment, even to the less attractive views. But distance does not lend enchantment to the spectacle of a Royal Family editing its hesitant and at times panic-stricken progress through the 20th century.

In an era when audio and video technology have revealed Fergie having her toes sucked, Charles cheating on his wife, and Diana rubbishing the Queen Mother, media intrusion into the private lives of royalty is a serious issue. The Royal Family does not help that case by guarding secrets from its past which, as it happens, are no longer secret. Queen Mary's raids on antique shops, where she would filch items without paying; the Duke of Windsor's activities in 1940: from the absurd to the sinister, the story can be told from sources outside the Royal Family's jurisdiction.

A more sensible strategy would be to transfer control of the royal archives to the Public Record Office. Material which is genuinely embarrassing to living members of the family could be withheld. Otherwise, a 30-year rule would apply. When the Queen Mother dies, to be followed in due course by the Queen and Prince Philip, their successors should also resist the temptation to commission official biographies.

These reforms would tax the resources of the archives' hard-working staff. But they would end the confusion in the Royal Family's mind between serving the nation and preserving discredited myths.

Divine Right: The Inglorious Survival of British Royalty by Richard Tomlinson is published on Thursday by Little Brown (pounds 18.99)

(Photograph omitted)