The real Coco Chanel

It is difficult to disapprove completely of the woman who invented the little black dress. And trousers for women. And sportswear as a fashion statement. And the sun tan. But there were many shadows in the long life of Gabrielle "Coco" Chanel. Not all of them are revealed in the French bio-pic of her early life which opens in Britain this Friday.

"Mademoiselle" Chanel was a public figure for more than half a century but she was also a compulsively secretive woman. She had much to be secretive about, including her flirtation – and, in the case of one senior German officer, her love affair – with the Nazis.

The understated Chanel style twice transformed the world of fashion, once in the 1920s and then again in the 1950s. "There is nothing so beautiful as emptiness," she said. But her advocacy of simplicity and sombre colours (and especially black) was also, it appears, a cloak for her own personal tastes and especially her taste for secrecy.

For many years "Mademoiselle" Chanel had a flat over her "workshop" in the Rue Cambon in Paris, where she spent every afternoon alone before returning to her suite in the nearby Ritz Hotel. When she died in 1971, aged 87, her private retreat turned out to be a riot of violent colour and Rococo sophistication, things that the public "Mademoiselle" Chanel claimed to despise. It was as though Pablo Picasso (a close friend) had been caught out with a secret stash of sentimental, 19th-century watercolours.

The movie Coco before Chanel, starring Audrey Tautou as the great woman, sidesteps most of this biographical untidiness by following only Gabrielle Chanel's early life.

She was born in Saumur on the Loire in 1883, not 1893 as she sometimes claimed. Gabrielle liked to say that her father was a businessman who left to seek his fortune in America. Albert Chanel was, in fact, a peddler who abandoned his family.

When her mother died, Gabrielle was 12 years old and she and her two sisters were placed in an orphanage. At 18, she moved to a convent where she was employed as a seamstress, a skill which would eventually make her one of the most influential women of the 20th century.

She initially tried to make her fortune as a music hall singer in a theatre in Vichy frequented by army officers and other wealthy young men. It was here that she acquired her nickname and the first of the two lovers who would help her achieve fame and fortune. There are several versions of the origin of her nickname. The most plausible is that, while she was a singer, her most popular act was a brainless song called "Qui qu'a vu Coco dans l'Trocadero".

The young Coco was a beautiful, slender woman, not unlike Audrey Tautou in looks. She had several lovers, culminating in a semi-official appointment as the second mistress of Etienne Balsan, a wealthy young man who bred horses. Although the relationship did not last long, it introduced her to high society and led to a long, sincere and very successful romantic and business partnership with an Englishman living in France, Arthur "Boy" Capel. Although Capel refused to marry her, he remained faithful, in his way, until his death in 1919.

He and Balsan helped to set her up, originally, in a hat-making business. She also became celebrated in the wealthy horse-racing world before the 1914-18 war for her revolutionary style of dress: no coloured silk and frills and, flowery hats but a slender, schoolgirl look in whites and blacks and, unthinkably, trousers or jodhpurs.

In 1910, Boy Capel loaned her the money to set up her first fashion salon in the heart of Paris. Her "new silhouette" designs for women – taking ideas and materials from menswear and sportswear for the first time – boomed in the anti-establishment mood after the war. The "flapper look" of the independent young women of the 1920s, including the slender figure and short hair, was mostly a Coco look.

Traditionalists accused her of "luxurious miserabilism", but she expressed in fashion the ideas of the modern movement. The secret of her success was, she said, "always to remove and to pluck, never to add. The greatest beauty is the freedom of the body".

Coco Chanel became such an icon that everything she did was copied. Until the 1920s, pale skins for women had been the vogue. When she returned accidentally sun-tanned from a holiday beside (of all places) the North Sea, the fashion changed. She was the first clothes designer to launch her own perfumes, including Chanel No 5 in 1921. Much of the investment, and the profits, for her perfume business belonged to a pair of Jewish entrepreneurs called the Wertheimer brothers. During the Second World War – one of several shadows on her reputation – "Mademoiselle" Chanel tried to use the anti-Semitic laws of the Vichy government to claim the business for herself.

When the Germans entered Paris in June 1940, Coco closed her fashion house and moved into the Ritz. She had a comfortable war in the arms of a convinced Nazi and intelligence officer, Hans Gunther von Dincklage. She was even involved in a hare-brained attempt to negotiate a separate British-German peace in 1943.

When France was liberated in 1944, hundreds of French women had their heads shaved and were paraded through the streets for alleged "collaboration horizontale" with the Germans. They were mostly poor women or prostitutes. Few rich women were attacked. Partly through pulling strings with friends in the British royalty and aristocracy, Coco avoided both official and unofficial punishment and fled, in disgrace, to Switzerland.

She relaunched her Paris fashion house in 1954 driven by her hatred of Christian Dior and the "New Look". She accused him of restoring the 19th-century ideal of women as pretty objects for the comfort of men. A woman sitting down in a Dior dress, she said, looked like "an old armchair".

Her business and influence boomed once again, the pink suit worn by Jackie Kennedy in Dallas on the day of her husband's assassination in 1963 was a Chanel creation. But most of her post-war customers and admirers were foreign.

The French never quite forgave "Mademoiselle" Coco, the woman who preached simplicity, for living an elaborately luxurious war in the arms of a German officer.