DESPISED: portrait of Wallis Simpson who was shunned by the royals

Wallis Simpson, the woman who has been painted as more scarlet than Miss O'Hara, more gold-digging than Lorelei Lee, and more despised by the British monarchy than anyone before or since, was, ultimately, a tragic and isolated figure burdened by a pathetic and over-dependent husband. At least so says a new documentary, Wallis Simpson - The Demonised Duchess, which is being screened tonight. The Wallis Simpson who emerges from this portrait is not a calculating social climber, but a bright and witty woman whose great love affair brought her as much unhappiness as happiness, and whose spirit was - to some extent - sapped by the pressure of trying to ''be a whole empire to a man''.

Dismissed by the Queen Mother as ''the lowest of the low'', the Duchess of Windsor has long been blamed for the abdication of Edward VIII: the closest she ever came to being accepted by the royals was when, in a display of hypocrisy rivalled only by their performance at Diana's funeral, they turned out to bury her. However, as The Demonised Duchess reveals, being frozen out by relatives was not a new experience for Wallis Simpson; she had been something of a misfit from the day she was born, just seven months after her parents' rather hasty marriage. Born Bessie Wallis Warfield, Wallis, who was a sharp-minded child, dropped her Christian name because, she said, ''so many cows are called Bessie''. The adoption of Wallis as her name was undoubtedly the first sign the girl had style; style but no money. And money - probably because she and her mother never had any of their own - was extremely

important to her. Indeed, she is credited with coining the saying: ''You can never be too rich or too thin.''

Her father died of tuberculosis when she was five months old, and Wallis and her mother were initially taken in by his well-to-do family, the Warfields of Baltimore. However, they were shunned by most of their relatives. At the first opportunity after she ''came out'' as a debutante - albeit the only debutante in town who didn't have a celebratory ball - Wallis got engaged. She was married to a Naval pilot eight years her senior when she was 20, but quickly discovered he was a violent alcoholic. When he was posted to China, she stayed at home and embarked on her first proper love affair, with a wealthy Argentinian.

In 1924, Wallis headed for China with a marital reconciliation in mind, but it was not to be. What exactly she got up to during what she later referred to as her ''lotus year'' is the subject of much debate. One of her biographers, Charles Higham, believes that, in addition to socialising and having affairs, she acted as a courier for the American Navy. She is said to have had health problems there and, while one source claims she had an illegal abortion while heavily pregnant with an Italian lover's baby, another believes she was hospitalised after her husband's abuse caused irreparable internal injuries. When, 12 years later, her involvement with Edward VIII was threatening to alter the line of succession, the British Prime Minister is said to have compiled a dossier on her ''scurrilous'' activities during her time in China.

Following her divorce, Wallis met and married Ernest Simpson, a British-American businessman with whom she settled in London. Within a few years, she encountered the Prince of Wales, the most eligible bachelor in the world. They began a relationship which bewildered many of their friends who could not understand why, when he could have his pick of girls, he would fall for this twice-married woman only two years his junior. When Edward became king, Wallis began to feel uncomfortable with their relationship - which was demanding more and more of her time. In September 1936, Wallis, worried by the intensity of Edward's feelings for her, tried to extricate herself from the affair.

The programme's experts reckon Wallis would have been quite happy to play Camilla Parker Bowles to Edward's Prince Charles, to be mistress rather than queen, and the consensus is that she did not put pressure on him to marry her. Instead, she begged him not to abdicate - which was, of course, the only way the king could marry a divorcee. She wisely foresaw their future when she pleaded with him by letter: ''I am so anxious for you not to abdicate and I think the fact you do will put me in the wrong light to the rest of the world.'' Despite her pleas, Edward abdicated on December 10, 1936.

One of the most touching of Wallis's own personal testimonies, which are scattered through the documentary, comes from a letter to her uncle. She says: ''I woke up and there was David [as Edward was known to friends and family] standing beside the bed with his innocent smile, saying: 'And now what do we do?' My heart sank. Here was someone whose every day had been arranged for him all his life, and now I was the one taking the place of the entire British Government, trying to think up things for him to do.''

Frozen out by the British royals, Edward and Wallis married, with only one relative present, in France in June 1937. They seem to have spent most of the rest of their married lives drifting between society hotspots, since they had no official royal roles to perform. When Edward died in 1972, Wallis went to pieces and gradually declined into a bedridden, near-comatose invalid, completely dependent on her staff and, especially, her lawyer who took the decision to allow no-one to see her. The once vivacious socialite died, alone, in 1986.

n Wallis Simpson: The Demonised Duchess, C4,

9pm tonight.