So what went wrong for the once great hope of the Windsors? There are so many moments that might be held up as the turning point from the `toe- sucking' to the plight of her cartoon character Budgie the Helicopter, to the recent revelation that she owes pounds 3m, that it is almost impossible to recall the Duchess' heyday.
According to her critics the signs were there from the very start, when she married Prince Andrew at Westminster Abbey in 1986. As she turned round, not to face the cheering crowds with a regal smile, but to tie a teddy bear to the back of their horse-driven honeymoon carriage bearing the couple off into their short-lived sunset, they knew.
Richard Barber, editor of OK magazine which is the rival of Fergie's great friend Hello!, said: "From that moment we knew we were in trouble and it was all going to go wrong. It was a question of there's a good sport and then there's Fergie."
For those who were anxious to see the royal family pulled into modern life, Sarah Ferguson, a thoroughly modern royal who had worked for a living in publishing, had a series of previous boyfriends and openly struggled with her weight, seemed the ideal antidote. The public was willing to at least give her grinning and hearty style a chance.
For many she symbolised the two conflicting world's of the royals, at once anxious to retain their dignity, but also eager to be seen to be relevant and up to date.
It was when Fergie came under the fiercest fire from the old-style establishment that she was often at her best, not least when the usually supremely gentle Lord Charteris said of her: "She is simply a vulgarian. She is vulgar, vulgar, vulgar, and that is that." Instead of retaliating the Duchess responded with dignity by responding she had always thought he was a very nice man.
However, it was a rare moment of wisdom in an otherwise chequered career as a leading player in the royal drama, constantly dogged by irritating follies, from entering into a food fight with bread rolls during a flight with her father, Major Ron Ferguson.
The most disturbing concern for the royals must have been the gradual realisation that Fergie was only playing at being a royal, in the same way that she played at being a chalet girl, a publisher, an author. The only thing she appeared to remain constant to was her love of going on holiday and, to her credit, her two daughters Eugenie and Beatrice.
When Fergie became the first royal to open her doors to Hello!, in an unprecedented step that showed her and her family in casual mode, it was clear she was lapping up the limelight. They posed in their modern palace, the newly-built Sunningdale that resembled an out-of-town Tescos, and invited the public in to see how normal they were.
Fergie was not normal. The truth was there for all to see. She had exorbitantly expensive bad taste, a voracious appetite for publicity, and swallowed up large amounts of money, but unlike the rest of the Windsors she did not even have a birth-right.
If there was a turning point in her own image, it was the long-lens shot of Fergie in the South of France, having her toe sucked by her `financial adviser', John Bryan, following her separation from Prince Andrew in 1992. Her remaining credibility nose-dived.
Although it was clear from the early high jinx of the Duchess of York that she was a potential time bomb for the royals, few could have anticipated the absurd depths to which the `toe sucking' incident would bring them down. With so many other catastrophes in the wings with the Prince and Princess of Wales, it was nothing short of a disaster.
The Duchess remained tenacious in her determination to retain a place in royal life. She continued to campaign for her children's charity, albeit with the coffers empty, and she continued to appear in Hello! constantly reinventing herself with new hairstyles.
Even in Fergie's darkest hour her most loyal followers believed she might be ressurected as a main player in the royal saga. However, her behaviour has continued to heap yet more embarrassment on the family she married into.
The Duchess had a series of arguments with her staff, and two aides left her, prompting speculation that while her status has sunk her behaviour has become more demaning and erratic. Her pursuit of Thomas Muster, the tennis star, around the world, has also caused blushes on her behalf.
Perhaps the saddest image of the Duchess of York was her latest reinvention in Hello!, a pale, emaciated shadow of herself.
Like the very first vulgarian, Thersites in the Iliad, a soldier who dares to talk back to his betters, she has received a sound beating for her vulgarity. But her followers insist, the Fergie story is not over yet.Reuse content