The return of Wallis Simpson

For a woman who played such a central part in Britain's biggest constitutional crisis, Wallis Simpson has had to content herself with a lot of supporting roles of late. But all that will change when arguably the most interesting queen we never had takes centre stage in a major new movie as well as two new biographies out later this year.

Despite hounding her out of the country 75 years ago, we cannot – it seems – get enough of this most controversial of temptresses, whose attentions cost a king not only his kingdom but also an empire. Such is the extent of Wallis-mania that the couple's former French country house, where they weekended from 1952 to 1972, has just become the most popular new retreat in the Landmark Trust's portfolio of holiday properties; you'll have to move fast if you fancy sleeping where the notorious couple once laid their heads because most weeks this summer are already booked.

Perhaps fittingly for someone who deprived a nation its king, the Duchess of Windsor's legacy has spawned a multimillion-pound industry: the £2,000 and upwards it costs to spend a week at Le Moulin de la Tuilerie, in Gif-sur-Yvette, 40 minutes south-west of Paris, is peanuts compared with the hundreds of millions raked in at box offices, but it all adds up.

Then there are her jewels: a sale at Sotheby's last November of 20 items of jewellery once owned by her and the duke fetched £8m. Her emblematic panther bracelet, made of onyx and diamonds, set a record for the most expensive ever sold, fetching £4.5m alone. And the original sale of her jewellery, in 1987, still holds the prize for the world's most valuable single-owner collection ever at more than £33m.

So far, film-makers have led the charge to cash in on the American's allure. Her bit part in Channel 4's Any Human Heart last autumn, which saw the duchess crop up first on a French golf course and later in the Bahamas, was swiftly followed by a small role in the BBC's remake of Upstairs Downstairs, which dwelled on the (unproven) rumours that she was sleeping with the then German ambassador to Britain, Joachim von Ribbentrop, who became the Nazis' foreign minister.

And who could forget the contribution that "that woman", as she was known, made to The King's Speech? Whether it's the American connection – Bessie Wallis Warfield, as she was born, hailed from Baltimore, Maryland – or something deeper, the movie is tantalisingly poised to become Britain's most successful ever with more Oscar nominations than any other home-grown film. Audiences are flocking: global ticket sales have already topped $200m (£123m).

Should The King's Speech triumph at the Oscars, expect American boasts that the story needed the catalyst of the twice-divorced Simpson even to exist to get louder still. The BBC's American arm has already jumped on the bandwagon with Katty Kay's Modern Monarchy: Here and There, which aired last month. And the theatre producer Michael Alden has an option on the original stage version of The King's Speech for Broadway.

With Hugo Vickers's sympathetic biography, Behind Closed Doors: The Tragic Untold Story of the Duchess of Windsor, and Anne Sebba's That Woman: The Life of Wallis Simpson, Duchess of Windsor, attention will switch briefly to the publishing world before returning to the cinema later this year with Madonna's W.E., a modern love story that mirrors that of Wallis and Edward. There's said to be no bigger champion of the duchess anywhere than Madonna – less generous souls like to dwell on the traits the pair share – so cinemagoers can expect a revisionist depiction.

Eve Best, who played the duchess in the version wowing Hollywood, admits her views are "very, very subjective", before adding: "I don't think she was a bad girl. I think she was like anybody else. She just happened to be a good-time party girl and a heck of a lot more fun than the people Edward had come across, and he fell madly in love with her. The problem was the circumstances. Actually, it was because his actions could be seen as bad, in such a delicate area – the way in which society allocates blame – that people have always allocated blame on her rather than him."

Anne Sebba, who is the first female biographer to tackle Simpson, says: "She's really quite a hard person to like, but I do think she deserves to be understood. No person could be all the vile things she's accused of being: a spy, a witch, a whore. The establishment put such heavy pressure on the image of Wallis that I knew she was ripe for a revisionist version. New material now available really does change one's perception of her."

Sebba believes the fascination lies in the duchess's illusiveness. "It's assumed she must have magic powers; that she must have hypnotised him. But nobody can put their finger on what it was about her. She wasn't even young; she was 40; she wasn't even beautiful. But clearly a woman who attracted three husbands must have had something." That something was rumoured to be a string of sex tricks learned in the brothels of the East, where she spent time with her first husband. The Shanghai Squeeze and Singapore Grip are both probably self-explanatory, but think "matchstick" and "cigar", and men, at least, might start to fathom her hold over Edward.

As for why the duchess is such a hot ticket right now, well, two words: William and Kate. The couple's nuptials have ignited monarchy fever even in arch-republicans and reminded a nation of what has gone before. Then, it was a controversial affair between the heir to the throne and an American divorcee; now the divorcee is English, but question marks still hang over her suitability to be queen. Juliet Gardiner, whose take on the period, The Thirties: An Intimate History, is out in paperback, says: "Queen Camilla and Queen Wallis both sound so bizarre somehow. With Prince William coming so much to the fore, people are beginning to wonder what we want from our royalty. Will the Queen abdicate? We're all now wondering whether Charles will ever come to the throne."

Gardiner also points to the parallels between the economic climate of the 1930s and that of today. "There's a lot of resonance; we have a lot of sympathies. And Wallis Simpson was the excitement of the 1930s. It was a wonderfully glamorous period and she is 1930s glamour."

With the 75th anniversary of the abdication this December, the duchess seems set finally to make up for all those decades in exile – even if it is too late for her personally to benefit.

Scandalous royal women

Princess Margaret Of the stories that exist about her sex scandals, none is murkier than that depicted in the 2008 film The Bank Job, which claims MI5 staged a London bank robbery to get rid of sexually compromising photographs of her.

Diana, Princess of Wales The People's Princess is set to get the cinematic treatment in two forthcoming biopics that will struggle to avoid the controversies in her colourful life.

The Duchess of Argyll The Duchess was the inspiration for Thomas Adès's chamber opera Powder Her Face, which includes a voracious fellatio scene.

Elizabeth I The award-winning TV miniseries named after the so-called Virgin Queen has fun first with Elizabeth's volatile relationship with her oldest friend, the Earl of Leicester, and then her affair with his stepson, the much younger Earl of Essex.

Alice Keppel The most famous mistress of Edward VII, the eldest son of Queen Victoria, is the great-grandmother of Camilla, Duchess of Cornwall. She was played by Moira Redmond in a 1975 TV series, Edward the Seventh.

Nell Gwynn "Pretty, witty Nell" remains the best-known mistress of Charles II, an orange-seller turned actress. Her life has inspired a number of plays, films and television dramas since her death in 1687.