Dame Joan Collins will be playing famous royal in The Bitter End - a new biopic portraying the controversial Duchess of Windsor’s final years.

Former 91, is the latest in a long line of women stars to play the American divorcee - often compared to - blamed for causing her husband VIII to abdicate in December 1936.

Though there are plenty of cultural offerings of the late royal's life, the years leading to her death from , aged 89, have seldom been portrayed. “I am thrilled about the challenge of playing this iconic woman in a previously untold story in what I’m sure will be a very successful endeavour,” says Joan.

First married, aged 20, to an alcoholic Navy aviator, the duchess then divorced and married English-American shipping executive Ernest Simpson in the late 1920s, before beginning an affair with Edward, then, who she went on to marry.

According to royal historian Tessa Dunlop, Joan - who she describes as “wonderfully effortful”- is the perfect choice for the role. She says: ”I can't think of anyone better to do Wallis justice.

"Joan is effortfully beautiful - she's not going to pretend she hasn't put a lot of time and effort into her look.

"And Joan is so sharp-edged - she's ninety but looks sixty. If Wallis was alive today, she would have Botox and have done everything to stay looking as glamorous as possible. She died lonely and there was something pitiful about her in the end, so The Bitter End title is apt."

Here, Tessa gives her verdict on other women who have played Wallis through the years:

Bonnie and Clyde star Faye Dunaway played Wallis, opposite Thorn Birds actor as Edward, in the TV film, charting the beginning of the royal romance.

Edward had said of their first meeting: "I was immediately impressed with her vivaciousness, wit and smart repartee. I particularly admired her complete frankness."

Of the film, which came out the year Edward died, Tessa says: “It captures that claustrophobic formality which Edward professed to loathe about royal life - and how besotted he became with Wallis.

"Richard is handsome as Edward was so, like the real Windsors, Faye and Richard cut a very glamorous couple. I also love that Queen Mary is a suitable ice queen - which she was!

"Also they have Faye begging him not to abdicate, which is what happened. She is depicted as distraught and she would have been. She was then trapped with this man in royal purgatory for the rest of time."

Told from Wallis’s point of view, the movie with Anthony Andrews playing Edward, wonan Emmy nomination. It tells Wallis’s story in flashbacks, starting with her 1972 arrival in Britain for Edward’s funeral.

Tessa says of Jane Seymour’s performance: “I think now we would see this as too soft on Wallis. It visually really works - the amazing costumes. It evokes Wallis's incredible sartorial presence.

"This film was more favourable to Wallis than more recent depictions, because in the eighties and nineties, the was seen as a bit of a mess with the Queen's children getting divorced - hence this softer view of Wallis. "

Joely Richardson plays an aloof Wallis, opposite Stephen Campbell Moore’s Edward, in this 2005 made-for-TV movie - the first to be told from the duchess’ viewpoint.

Tessa believes this is the most accurate portrayal of the divorcee, saying: "She's flirtatious, straight talking and ambitious, which is exactly who Wallis was - but also quite vulnerable to Edward's insistence she leaves her second husband Ernest Simpson.

“Wallis didn't want Edward to abdicate - she was quite happy to be the mistress, but he kind of gave her no choice. "

Tessa also feels Joely Richardson captured her physically, saying: "Joely isn't a natural beauty, but has that outstanding look - she is striking like Wallis."

No stranger to depicting formidable women, having played Margaret Thatcher in series The Crown, one critic described Gillian Anderson’s Wallis as a "paranoid psycho-snob" in this Bafta-winning drama.

The William Boyd TV adaptation of his novel is a fictionalised account of the life of Logan Mountstuart, a writer who crosses paths with many influential figures of the 20th century, and Wallis is not a central character - but makes an impact nevertheless.

Tessa says: "I think this is a caricature version of Wallis - the paranoid snob was her Victorian armour."

Eve Best, who plays fierce Rhaenys Targaryen in the HBO drama House of The Dragon, was "just not beautiful or edgy enough" for the role, according to Tessa.

"Where is the sharp glamour? " she asks. "Helena Bonham Carter, who plays Queen Elizabeth should have been Wallis and vice versa.

"The problem with The King's Speech is the heroine is Helena Bonham Carter, because she's saving her husband. And it's a classic British portrayal. In recent years we flatter the Royal Family. The older films with Jane Seymour and Joely Richardson were much braver."

But the extreme dislike between Wallis and the Queen Mother, who thought she was a gold-digger, was accurate, according to Tessa.

"Women had few choices for earning money, so marrying well was Wallis's route - although she did truly love Edward,” she says. "Also, Wallis was fun and sociable, as we see her here. She was a very generous host and entertainer."

Written and directed by Madonna, the film examines Wallis and Edward's love story through the eyes of a woman who becomes obsessed with their romance.

"This one is about the cautionary tale of fame and riches." says Tessa. "Edward tells her to try and enjoy the press attention, but actually he hated it. Wallis was in some ways better equipped to manage it than him. She had her costumes to hide behind and the brooches.

"They use some of Wallis's real jewellery and you can see why Madonna was drawn to making the film - they were both similar in that they were properly famous and hung out with all the top designers and names.

"Andrea is very young - the opposite end to Joan Collins's portrayal. But, as the new film will bookend Wallis' life, this will serve as a reminder that her standards never slipped."

actress Lia Williams played Wallis opposite Alex Jennings as Edward in The Crown - but Tessa thinks she was woefully miscast.

"She just was not stylish enough,” she says. “Wallis said herself that she wasn't a beautiful woman - but she had exquisite sartorial style. Combined with money - and she had plenty when she married Edward - she was able to exude a very sharp glamour."

Tessa is also critical of s depiction of the portrayal of the couple as Nazi sympathisers - and she accuses the programme makers of being hard on them, as they were “easier targets” than other royals.

"I really didn't like how The Crown really ramped up the Nazi connection,” she says. Wallis and Edward were much softer easier targets to go for - people already condemned by the royal family itself.”

A Bitter End is due to start shooting soon in London and Paris and a release date has not yet been revealed.