As the 100th anniversary of Hemingway's birth approaches, Brian Donald exclusively reveals that the woman upon whom he based Lady Brett Ashley in The Sun Also Rises was not all she seemed For whom the belle told lies

This was the same lady for whom Hemingway developed an unrequited passion while spending part of 1924 at Spain's San Fermin bullfighting festival and whom ''Papa'' Hemingway fictionalised as Lady Brett Ashley in the 1925 novel The Sun Also Rises, the same hard-drinking adventuress portrayed by Ava Gardner in the 1956 film version of Hemingway's book which also featured Tyrone Power, Errol Flynn, and Mel Ferrer.

What then were the Edinburgh crimes of this beautiful, alluring but dissipated Anglo-Scottish woman?

These are crimes which have lain undetected even by leading American scholastic Hemingway biographers such as Professor Carlos Baker, who wrongly states in his 1969 biography that Duff Twysden's marriage at Edinburgh's Manor Place off Atholl Crescent took place ''in January 1917 in London while Ernest was still in high school''.

To answer this, one must accept in advance that by the time Duff Twysden arrived with her husband-to-be, Royal Navy lieutenant Roger Twysden, at Edinburgh's Caledonian Hotel to establish prenuptial residency qualifications in Scotland, she was well practised in the arts of deception.

Not only had she been employed by the British secret service in the months preceding her matrimonial journey north of the Border to Auld Reekie, but she had actually met Roger Twysden when the latter was also assigned to naval intelligence.

So the path of romantic falsehood was already well-worn by this Yorkshire lass, born plain Dorothy Smurthwaite, daughter of Baines Smurthwaite, a licensed grocer who is magically but falsely transformed into being a ''solicitor'' on the Edinburgh marriage certificate of Thursday, January 26, 1917.

Dorothy Smurthwaite, the future Lady Duff Twysden of Hemingway's Spanish circles, had a mother who came from a prosperous Scottish middle class background. In fact, her mother, Charlotte Stirling, was reputed to have aristocratic pretensions which she had clearly passed on to her wayward daughter.

Again, this future Spanish bosom companion of Hemingway had divorced her first husband, Luttrell Byrom, in 1916, yet on her Edinburgh wedding certificate a year later she brazenly described herself as a ''widow'', thus committing a second criminal offence of misrepresentation under the Births, Deaths and Marriages Act (Scotland).

Nevertheless, such offences were mere peccadillos to an adventuress who was determined to transform her mother's social climbing fantasies into a daily personal reality by marrying into the minor English landed gentry as represented by the Devon-based Twysdens of Churston House.

So, in the best modern soap-opera fashion, money and enhanced social position were the catalysts which provoked this beautiful and charming temptress into brazenly flouting the matrimonial laws of Scotland as she and her beau stood in the house at 49 Manor Place in Edinburgh's West End before Rev R H Fisher of St Cuthbert's Parish Church.

There, Dorothy Smurthwaite and Roger Twysden were married ''according to the forms of the Church of Scotland''.

No doubt the future Lady Duff Twysden displayed to minister and suitor alike that same brand of fatal charm that so captivated Hemingway, enough to make him want to immortalise her in his first major novel.

However, someone who was not fooled by the Smurthwaite charm was Roger Twysden's mother, Jessie. So forcibly did Jessie Twysden reject the gold-digging aspirations of her potential daughter-in-law that she drove the loving couple to Edinburgh.

Again, Jessie Twysden's attitude was also partially responsible for the blatant falsehoods of the 1917 Edinburgh marriage certificate - fictions no doubt fed by Duff Twysden herself to throw those curious about her past off the scent of truth.

Nevertheless, the first way in which Jessie Twysden's implacable opposition to Dorothy Smurthwaite, alias Duff Twysden, prompted her unwanted daughter-in-law to muddy the waters of future scholarship and break the marital laws of Scotland lay in the fact of Jessie's own religious persuasion. The Twysdens were staunch members of the Church of England, and shared that same established-church hatred

of divorcees that would later ultimately cost Edward VIII his throne in 1936.

Secondly, as landed gentry they would almost certainly have despised the daughter of a mere licensed grocer - hence the double falsehoods of ''widow'' instead of the more accurate ''divorced'', and ''solicitor'' instead of ''licensed grocer'' in the occupation sections of the Edinburgh marriage certificate.

These Marriage Act offences were clearly an attempt by Duff Twysden to curry favour with her mother-in-law.

None the less, Jessie Twysden's forecast that the marriage of Dorothy Smurthwaite and her son would not last was prophetic.

The marriage contracted that January ended in England within a few years in a welter of alcoholic dissipation and acrimony.

By the time Hemingway first encountered Duff Twysden in Spain in 1924, she was living with her equally dissolute cousin, Pat Guthrie, a notorious sponger and drunkard who would be impersonated by Errol Flynn as ''Mike Campbell'' in the 1956 movie of The Sun Also Rises.

Nevertheless, despite being initially infatuated by Duff Twysden, Hemingway soon tired of her incessant attempts to cadge money and drink from him in Spain.

Again, there was to be no happy ending for this amoral Cinderella. By 1933 she had met and married an American painter, Charles King, with whom she lived until her death, aged 43, from tuberculosis on June 27, 1938 at Santa Fe, New Mexico.

Meanwhile, the ghost of Lady Duff Twysden is still beguiling and fooling modern American biographers of Hemingway, particularly those responsible for three large biographies published since 1986.

All three biographies faithfully repeat the Duff Twysden-inspired fiction that Roger Twysden, her Edinburgh marriage partner, was a baronet - he wasn't. English baronets always append the letters ''Bart'' after their surnames. No such appendage appears on the couple's 1917 Manor Place wedding certificate, either for Twysden father or son.

The same trio of Hemingway biographers also regurgitate the fiction that Roger Twysden was ''a senior naval commander'' when he wed Duff Twysden - in contrast, the 1917 Edinburgh wedding certificate clearly states that the groom was a Lieutenant attached to HMS Petard.

Nobody would enjoy more her posthumous capacity at a remove of 61 years to put the cat among the academic pigeons on the subject of her place within the life of her erstwhile Spanish drinking companion Ernest Hemingway than Dorothy Smurthwaite, alias Lady Duff Twysden, alias Lady Brett Ashley, cynical flouter of Scottish matrimonial laws in Edinburgh in 1917.

Finally, the Scottish-related fictions about the American literary icon do not end with the inaccuracies exposed by Duff Twysden's 1917 marriage certificate.

Hemingway himself and various members of his family and other biographers claimed that the author's father, Clarence Hemingway, studied postgraduate medicine in Edinburgh in 1895. This is another fiction that should be expunged from all future Hemingway biographies.

The Special Collections Department of Edinburgh University Library has a list of every American doctor who did postgraduate medical studies at the university going back to 1756.

Hemingway's father's name does not appear on these lists, nor on the lists of the Scottish Royal College of Surgeons library in Queen Street where the only reference to Hemingway senior is in a 1906 vintage directory of North American doctors then in general practice.

So let us hope that in this, his centennial year, those celebrating Hemingway's life with so-called ''definitive'' biographies will avoid repeating the errors exposed by the 1917 Edinburgh marriage certificate of Duff Twysden, alias Dorothy Smurthwaite, and the post-graduate medical records of Edinburgh University and the Scottish Royal College of Surgeons.

n Next Thursday in The Mix, Hugh MacDonald looks at the story behind Hemingway's recently published, long-lost novel.