Re-making an icon as famous and beloved as Chanel No. 5 was never going to be easy.

On a chilly July morning during Paris Haute Couture week, in an old townhouse near the posh Paris district of Place Vendome, anticipation hung thick and heavy in the air. Quiet chatter tinged with impatience drifted from the clusters of journalists who stood waiting along the staircase, in the corridors and the doorways. They were all there for the same thing - what was arguably perfume royalty: Chanel was about to unveil the new incarnation of No. 5, which was first created in 1921.

Gabrielle Chanel, or Coco as she is commonly known to most people, once said: "A style does not go out of style as long as it adapts itself to its period. When there is an incompatibility between the style and a certain state of mind, it is never the style that triumphs

Just as fashion changes to reflect the sensibilities of the era, fragrances, too, need to evolve - even one as seemingly untouchable as No. 5. This was the rationale behind the decision to give the classic a more modern companion.

The original is after all, one of the most cherished touchstones of the Chanel brand, right up there with the tweed jacket and 2.55 bag. The new addition to the No. 5 family will have more pronounced differences than the Eau de Parfum and Eau de Toilette. But it does not replace the classic.

In a room where all the perfume oils used in the original No. 5 were displayed in stopper glass bottles. The famous jasmine and May rose absolute, ylang ylang, neroli, vetiver and vanilla were there, among others. And, of course, the Alde Hyde that plays such a crucial role in giving No. 5 its distinct character.

A run-down of each one - why it was chosen, what made it special - followed by whiffs of their individual aromas. On their own, none really smelt like the final product.

After that, we adjourned to a room which screened a video montage of No. 5 through the years. Archive photographs of Coco Chanel, the people involved in No. 5's creation various advertising campaigns and the women who fronted them flashed. Ali McGraw, Lauren Hutton. Catherine Deneuve and Nicole Kidman - all of whom embodied the spirit of the fragrance with their confidence individuality and grace.

When these initiation rites were complete, we were finally brought to meet the sating debutante in a cool, dark room where snowflake-shaped mobiles made from scented strips of paper dangled from ceiling to floor. In the middle was a black lacquered oblong block with an inverted pyramid suspended above it like a chandelier. Drops of liquid dripped slowly from the sharp tip, gathering in an overflowing pool on the block's top surface.

A fragrance that was both familiar and novel at the same time emanated from this elegant centrepiece. We were each handed a scent strip and invited to dip into the dark gleaming pool so that we could savour the scent more closely.

There was no denying the resemblance to No. 5. It has the same lush, floral tones, smoothness and elegance. But this fragrance was lighter, fresher. Compared to the original's womanly sophistication, it came across as more tender and Youthful, the strong Alde Hyde notes of No. 5 having been reined in and softened. Its name: No. 5 Eau Premiere.

It is impossible to understand the significance of reinventing No. 5 into Eau Premiere without knowing the original fragrance's rich, romantic history.

Back in 1921, Chanel - or Mademoiselle as she is still respectfully called by the brand's Parisian staff today - wanted to create a perfume that was radically different from the floral fragrances common - used by women, something that could not be pinned down to any particular flower. She wanted, in her words, "a highly distinctive fragrance... a woman's fragrance that smells like a woman".

"I want to give women an artificial perfume," she said at the time. "Yes, I really do mean artificial, like a dress, something that has been made. I don't want any rose or lily of the valley; I want a perfume that is a composition."

To do this, she collaborated with Ernest Beaux, a gifted perfumer from Russia. Beaux was just 17 when he started his career with a French company that made perfumes for the tsar's court. After the Bolshevik Revolution, he fled to France and settled in La Bocca near Grasse, where much of the country's perfume industry was based.

Beaux presented Chanel with a set of 10 fragrances, numbered from one to five and 20 to 24. It was the fifth bottle that she picked as her favourite. The number "five" also happened to be her luck, number and she was about to launch her collection that year on the fifth of May. So in line with her superstition, she kept the perfume's laboratory reference and named it simply, No. 5. The non-fancy name was also a nod to a stark declaration of independence.

Chanel didn't want No. 5 to be copied by anyone. To ensure its exclusivity, Beaux used the most expensive flower oil at the time in its formula -jasmine absolute. In fact, he used so much of it that the fragrance was simply too expensive for others to imitate.

But to balance the head jasmine scent. Beaux had to put in massive amounts of Alde Hyde - a cool, metallic-smelling synthetic ingredient. It was the first time such a large quantity was used in a perfume. The result was a scent that was unique, multi-faceted and impossible to define, much like a woman. It had no obvious top, middle or base notes, as its various elements existed in harmony rather than layers.

Chanel had indeed succeeded in creating a perfume that did not exist in nature and smelt distinctly different from its peers. But No. 5's scent was not the only thing that was revolutionary. Just as her little black dress and jersey sportswear liberated women from corsets and frilly gowns her perfume was a modern creation that was ahead of its time.

Drawing on the clean design of men's cologne bottles, No. 5's packaging was minimal and graphic. Chanel hated the fussy, overly-ornate containers that women's perfumes came in and felt that what was more important was inside them. As she said in a 1923 interview with Haiper's Bazaar "simplicity is the keynote of all true elegance". No. 5's bottle design was deemed so revolutionary, in fact, that it has earned a place in the permanent display collections of New York's Metropolitan Museum of Art.

As the popularity of No. 5 grew over the years so too did the number of stories that surrounded it, elevating it to near-mythical status.

After World War II, American GIs in Paris would queue outside Chanel's flagship store at 31 Rue Cambon - where it still stands - for a bottle to take home to their sweethearts. It was seen as a symbol of both victory and seduction.

During the 1950s, sales apparently shot up after Marilyn Monroe, when asked in an interview what she wore to bed, replied, "a few drops of No. 5.

And even today, the fragrance continues to be one of the best-selling perfumes in the world, with one bottle reputedly being sold every 30 seconds.

For Chanel herself, the fragrance was to be a creation she held extremely close to her heart. On her instructions, the staff at Rue Cambon would scent the store's curving, carpeted staircase with No. 5 every morning before she arrived. She was also frequently photographed on this staircase, usually on the first or fifth step in a special nod to No. 5, her very first fragrance.

With such a rich heritage - and the expectations of No. 5's legions of fans - it's no wonder the launch of Eau Premiere was met with intense anticipation and anxiety.

But Jacques Polge, who has been the "nose" of Chanel for the past 30 years, says the re-invention is necessary. He cites Chance and Coco as examples of younger, fresher Chanel fragrances that have been highly successful. "Light fragrances are what you have to do today because the opposite would be heavy, and a heavy fragrance is old and past," he says.

Ernest Beaux himself re-interpreted No. 5 once with the Eau de Toilette version. Polge later came up with the Eau de Parfum. Eatt Premiere is simply the latest rendition of No. 5. like a classic song being sung in a new way by a different artist.

Christopher Sheldrake, Polge's deputy, says: "The new Eau Premiere is for those who may associate No. 5 with their grandmother, or think it's too classic a scent."

"We kept the same ingredients, but used fresher, more transparent versions of the notes," he explains. So while the fullness of jasmine and May rose can still be detected at the heart of Eau Premiere, it is now tempered with greener undertones of roses from Turkey and Bulgaria. The intensity of the ylang ylang from Cornores has been toned down, and the coldness of the aldehydes has been tamed to produce a warmer scent.

If No. 5 was an oil painting, Polge imagines Eau Premiere as the watercolour version: lighter, airier, more transparent. He also had an image of the morning deer, which brings some of its softness to No. 5's bouquet of abstract flowers and gives it a more delicate facet.

Polge suggests wearing Eau Premiere in the day, while No. 5 could be reserved for the evening. "When No. 5 was created, it was in extract form because perfume at the time was very precious. One drop behind the ears and between the breasts. Now, people are using perfume all day- long. Eau Premiere is for daily use," he says.

Diehard fans of No. 5 may feel that Eau Premiere lacks the formers sophistication; that caber-cool, powder, quality created by the aldehydes. But its warmer, more floral nature is also what makes it more accessible and inviting for new users.

"No. 5 is the most complex Chanel perfume because it uses a lot more natural flowers but does not relate to a precise scent of a flower," he says. "The abstractness of No. 5 is what Chanel said - it smelt like a woman. Eau Premiere is like a young woman."