File photo: Mannequins display black outfits and jewellery from French fashion house Chanel's 1932 collection during a press-view of Mademoiselle Priv�, a joint exhibition presented by CHANEL and Karl Lagerfeld, at the Saatchi Galler.
File photo: Mannequins display black outfits and jewellery from French fashion house Chanel's 1932 collection during a press-view of Mademoiselle Priv�, a joint exhibition presented by CHANEL and Karl Lagerfeld, at the Saatchi Galler.
File photo: Mannequins display haute-couture outfits by Fench fashion house Chanel during a press-view of Mademoiselle Priv�, a joint exhibition presented by CHANEL and Karl Lagerfeld.
File photo: Mannequins display haute-couture outfits by Fench fashion house Chanel during a press-view of Mademoiselle Priv�, a joint exhibition presented by CHANEL and Karl Lagerfeld.
File photo: Mannequins display black outfits and jewellery from French fashion house Chanel's 1932 collection during a press-view of Mademoiselle Priv�, a joint exhibition presented by CHANEL and Karl Lagerfeld.
File photo: Mannequins display black outfits and jewellery from French fashion house Chanel's 1932 collection during a press-view of Mademoiselle Priv�, a joint exhibition presented by CHANEL and Karl Lagerfeld.
A woman poses for a photograph with an installation dedicated to the Chanel No. 5 perfume during a press-view of Mademoiselle Priv�, a joint exhibition presented by French fashion house Chanel and Karl Lagerfeld.
A woman poses for a photograph with an installation dedicated to the Chanel No. 5 perfume during a press-view of Mademoiselle Priv�, a joint exhibition presented by French fashion house Chanel and Karl Lagerfeld.
A man takes a photograph of mannequins displaying haute-couture outfits by Fench fashion house Chanel during a press-view of Mademoiselle Priv�, a joint exhibition presented by CHANEL and Karl Lagerfeld.
A man takes a photograph of mannequins displaying haute-couture outfits by Fench fashion house Chanel during a press-view of Mademoiselle Priv�, a joint exhibition presented by CHANEL and Karl Lagerfeld.
File photo: Lady Amanda Harlech and Designer Karl Lagerfeld attend the 2007/8 Chanel Cruise Show Presented By Karl Lagerfeld.
File photo: Lady Amanda Harlech and Designer Karl Lagerfeld attend the 2007/8 Chanel Cruise Show Presented By Karl Lagerfeld.

London - Lady Amanda Harlech is whip-smart, rake-thin, dark-haired and - always - impeccably dressed.

Her age? No idea - you can tot up her years of experience (12 years with John Galliano, almost 20 at the right-hand of Chanel's creative director Karl Lagerfeld) and realise, unless she started work at six, she looks far younger than whatever it actually is.

Today she's wearing feathered couture (ready for the evening party) to tour an exhibition based on the life of Gabrielle “Coco” Chanel, for whom she almost seems a contemporary reincarnation - not least because of her work alongside Lagerfeld at that label.

So it's fitting that Harlech is my guide through this new exhibition at London's Saatchi gallery.

It's another example of a fashion house taking over the curation and presentation of their own legacy - Louis Vuitton are doing it over on the Strand with their Series 3 show (open until 18 October), while Chanel has installed itself at the Saatchi once before for a photographic ode to its Little Black Jacket, drawing in around 165 000 visitors back in 2012.

That exhibition spanned a single floor: today, they have three, the top one devoted to workrooms teaching attendees how to embroider, create a Chanel camellia or brew up a batch of No 5. The specialist craftspeople have been imported especially from Paris for this expansive, expensive exploration into the life, love and label of Gabrielle Chanel.

I can't help but think of Saatchi as representing the most commercial of art, which ties in well with fashion, combining the creative with the commercial in lucrative matrimony. Chanel is one of the most successful combinations - the company is privately owned by the Wertheimer family, who originally bankrolled Chanel's extraordinarily successful expansion into perfume in 1924.

That perfume is well-represented here, obviously - “Hmm... I recognise this smell,” says Harlech, innocently, as we cross into the No. 5 room, where great glugs of the stuff bubble in vats, like an olfactory version of Willy Wonka's Chocolate Factory. The other areas of focus are haute couture and haute joaillerie, namely the recent re-edition of a 1932 fine jewellery range (the only one Chanel ever designed), and pieces from the house's celeb-heavy autumn/winter 2015 couture collection. Not the catwalk clothes, but the ones modelled by Julianne Moore, Kristen Stewart, Lily-Rose Depp and the like, designed specifically to show off that jewellery.

There's another room of quieter garments, focusing on extraordinary craft - what Harlech dubs “the impossibility” of couture, which includes a dress of solid gold thread. Estimated cost: £120 000.

The downstairs is an immersive experience, recreating the mirrored Art Deco staircase of Chanel's Rue Cambon HQ and her Coromandel screen-lined apartment walls. A facsimile of that apartment - now a designated museum site in France - magically appears on your phone as you travel through the room, thanks to a hi-tech app Chanel has launched in tandem, which also does away with the need for pesky museum signage.

“Beyond!” was Harlech verdict as she wafted it about the room. It's her first time seeing it, too. The ghost of Coco is ever present: her guttural, Gauloise-throttled voice dispenses her eternally utterable bon mots in every room. It's actually the actress Geraldine Chaplin, who has appeared as her in a few short films by Lagerfeld. One is screened here too.

The exhibition is titled Mademoiselle Privé. The name is drawn from a sign on the outside of Chanel's office door - it makes an appearance in the exhibition, opening as if by magic via the app. But applied to the woman herself, it's a paradox. Although Chanel was intensely private, fabricating elements of her life to shroud even the most base of facts (birthplace, birthdate…), it is that life on which the globally recognised iconography of the brand is based.

The orphanage she was raised in (which she would regularly reduce to a convent school, or deny ever having spent time in) was the source of the double-C logo, of her skill at hand-sewing, of the burgundy lining of her 2.55 handbag (apparently, her uniform was that colour). Chanel itself has sent it up - in 2013, Lagerfeld staged an “Art” show, with a backdrop of ersatz modern art inspired by Chanelisms of leather-twined chains and cardigan jackets. In a meta fashion moment, a few of those are installed in Saatchi galleries normally reserved for real-life Olenburgs and Lichtensteins.

Coco opened it up to public scrutiny herself, even creating faux gems inspired by those gifted to her by her lovers the Duke of Westminster and Arthur “Boy” Capel. The riding attire sported by latter, the love of Chanel's life, influenced her no-nonsense practicality; the former gave a touch of Britain, the hardy tweeds she would use for her suits.

“Chanel was all about the liberty of the British woman,” says Harlech. “Who, yes, she's eccentric. Why is she eccentric? She breaks rules… she's free.” She could be talking about herself - or indeed, Coco Chanel. The exhibition's opening gambit is an English garden specially devised by Chelsea gold-winners the Rich brothers. One section is planted to represent “Liberty”, of which Chanel had plenty.

“Chanel loved the British,” continues Harlech. We begin to pass through the exhibition. “Maybe it is the logic of British dressing. Dressing for the elements,” says Harlech - thinking of that garden, maybe.

“She was all about an athleticism, of a sort of boho art movie, hanging out with Stravinsky, with Cocteau. There was an exchange of ideas, which played back into her collections.”

Not so different to Lagerfeld enlisting all those A-listers to model his Chanel gear - although I'm not sure what they're bringing to the table, bar looking good in his clothes and Chanel's jewellery. And a lot of extra attention, of course.

This exhibition is all about garnering attention for Chanel - but it also imparts knowledge. The app whirrs in your hand and unravels the Chanel mythology: cross the Chanel “Totems” and it'll tell you about the stories behind Chanel's lucky numbers, her pearls and camellias. It may inspire you to buy a camellia of your very own, or some Chanel perfume.

But - and this is clever - it doesn't feel like that is the sole purpose of this exhibition. And that's satisfying.

Mademoiselle Privé is open until November 1, 2015 at the Saatchi Gallery, King's Road SW3, 10am-6pm daily (10pm on Wednesdays). Admission free

The Independent