Based in Shropshire and moving between her country home, London and Paris, Lady Amanda Harlech, muse, friend and co-conspirator to fashion's reigning don, Karl Lagerfeld, leads a charmed life. The creative consultant and writer has been privy to the inner sanctum of some of fashion's biggest stars, including John Galliano during his years as an independent couturier. Her title comes from a marriage to Francis Ormsby-Gore, 6th Baron Harlech, from whom she is now divorced.

In person though, despite her large couture-filled wardrobe, Harlech is more down to earth than you'd imagine. "It's not about being pinioned into something that you can't breathe in - like a passive muse on a pedestal," she says in a husky, plummy English accent. "Just being the object and not the subject - I'm really against that."

Catching her on a crisp morning in Tokyo, her eyes are gleaming and her banter witty. She exudes a cool confidence and it's easy to see why she might inspire the likes of Lagerfeld and Galliano. She read English at Oxford University, specialized in the work of Henry James and literature informs her fashion outlook.

"I've always approached things in a narrative way," Harlech elaborates, "in fashion it's telling a tale through cloth, a narrative with a beginning, middle and an end."

Even before she started university, the power of the image had a major effect on Harlech. She pored over fashion magazines and wanted to be one of those girls modelling on location. When she met Sophie Hicks - an architect-turned-fashion editor and the mother of model Edie Campbell - Harlech was instantly intrigued.

"I felt that it [fashion] was a more direct way of touching or moving somebody than writing a novel or a poem," she says. "I remember being an unpaid assistant, making tea for Sophie, and thinking, 'This is what I want to do more than anything'."

Harlech started working at Harper's Bazaar from the bottom up in pursuit of her dreams. She adjusted to her duties as "the skivvy in the fashion cupboard job" and quickly learnt the basics of her discipline, "along with other skills like ironing".

She met Lagerfeld, at one of his legendary parties during Paris Fashion Week, years ago, when she was still working with Galliano.

"When Karl was living at 51 Rue de L'Université, he would throw a party for anybody who caught his eye - an incredible mix of people, an open house - a highlight of fashion week."

Harlech calls the meeting a blessing, indeed when she had trouble sealing a Dior contract after Galliano joined the French house, it was Lagerfeld who came to the rescue, in 1996, for a contract with Chanel.

It might be easy to count the years of her influence but it's harder to pinpoint her role at Chanel - even for Harlech. "Muse" she decides is a rather contentious phrase; "maybe court jester" she jokes. "It's very difficult to describe, it's not being a stylist, it's not being an editor, it's not being anything really except somebody who sees. It means having a sense of proportion." "There is no title, not really," adds Harlech after a few minutes of trying to define the role.

Her own style is admittedly "quite strict". She is often seen in necklines so high they're almost Elizabethan and sharply cut outfits in black or monochrome - a rather severe, if also beautiful, vision.

"My favourite [Chanel] pieces would be ones that go with the essence of Karl's design ... a distillation of a collection if you will rather than the great show-off pieces."

She admires the complex embroidery and hero pieces, but for her personal style, she is "too much of a realist. I'm indelibly practical."

The close relationship with Lagerfeld has given her many chances to be creative at Chanel. The most recent was a three-week trip to India for Lagerfeld's long-time publisher and friend Gerhard Steidl. Travelling in India, what she calls her "photographic gesture", will be released this month.

Beyond that resides the allure of the legendary Coco Chanel, who like Harlech, indulged a passion for riding horses. "I agree with her whole rebellious thing," she says, raving about Chanel's "courage, fighting spirit and ingenuity".

"Taking men's underwear and making clothes out of it, taking what should be only worn for mourning, or menopause in the Mediterranean countries and making it the coolest dress - how fabulous is that?", she says. "None of us would wear black as much as we do if it weren't for her."

Coco Chanel's story of surviving heartbreak and breaking the boundaries of women's fashion from Edwardian corsetry and bows is particularly inspirational. But, it is their shared love of uniforms and horses, wherein lies a natural affinity. Chanel and the Duke of Westminster, who lives in the county next to Harlech's, were once lovers, she adds, meaning, "I've jumped the same hedges as her!"

Whether true or not, it makes for a good story. She does wish though, the current fashion industry would have more of "a narrative".

"When you take designers in and out of fashion houses so quickly, like the trend of recent years, such a narrative rarely forms well."

"What is Givenchy?" she asks. "I think that Riccardo [Tisci] is making it; what we are seeing is the Givenchy narrative emerging now - this incredibly strong but also fragile, thin, gothic woman. It is forming."

In an aside to the unceremonious dumping of Galliano at Dior, following his drunken, anti-Semitic rants, Harlech says "the sense of soul, the spirit, the narrative" was lost in subsequent collections, though that was before Raf Simons' appointment.

"It's survival of the fittest," says Harlech. "For any artist, if you are expecting a ka-ching immediately that puts huge pressure on the creative process. It doesn't always happen. Profit and design make an uneasy marriage."

"The stronger the base, the higher you go. You hothouse it and the stalk will bend. That's what's happening now. You see over-fertilised new designers and it topples over."

"People aren't building new things," Harlech quips, "they keep inhabiting other houses and renovate the interiors."