Harlech says: 'People think of me as a stereotype: muse, privileged, decorative'

Easy to say from a dressing-up suite at the Paris Ritz – but fashion's first lady is no pampered muse, as Chanel's new couture collections are set to prove.

Lady Amanda Harlech is the victim of many misconceptions. First and foremost is the fallacy that fashion really isn't much work at all – something with which a hard-nosed professional working through nights to pull together not one but two major collections for a four-week catwalk circus can wholeheartedly disagree.

There's also the misconception about Harlech's actual role in those collections. The popular myth has her jet-setting from a vast country pile in Shropshire to a vault of a couture wardrobe at the Paris Ritz, where she galavants about a capacious suite frocking herself up to inspire Karl Lagerfeld, at whose right hand she has sat for the past 15 or so years.

Perhaps it all arises from the label most often attached to Harlech: muse. "People think of me as a stereotype: muse, privileged, decorative," she says wearily, and warily. "Classically, the muses were the inspiration. They'd come and go – they wouldn't actually make things, get their hands dirty. I don't think I'm a muse, although I think I can help pull a trigger. I really like getting my hands dirty."

Harlech has been getting her hands dirty for nearly three decades – first alongside British design genius John Galliano during his tumultuous first decade in business (she was with him long before the scandal which led to his dismissal, from his graduation through to his appointment to Dior in 1996), and more recently as Lagerfeld's "outside pair of eyes" (his words) at Fendi, during his occasional consulting stints for luxury brand Hogan, Coca-Cola and Macy's, but primarily at Chanel, the most celebrated fashion house of all. Certainly, Harlech's influence will be felt when that great name unveils its spring/summer haute-couture collection in Paris this week.

So let's shatter some of those myths. First of all, the suite is in fact a spacious but serviceable fourth-floor room – Harlech herself shouts out, "Tell them about the glamour of me washing my hair in the sink and getting changed in the bathroom!" while doing just that. Why the Ritz? It happens to be across the rue (Cambon, that is) from the headquarters of Chanel – so conveniently placed that Mademoiselle Chanel herself lived here.

The "decorative" epithet Harlech complains of comes, perhaps, from a lingering Anglo-Saxon puritanism about an obvious love of appearance. It's not to say that Harlech is vain – although she's strikingly handsome, hair pulled back from fine-boned face with a jaw line you could facet diamonds on – but she definitely loves dressing up. While I'm sweltering in a black T-shirt on an unseasonably warm winter's day in Paris, she is dressed in a plissé slip of Chanel chiffon as underskirt to a billowing broderie anglaise dress and Edwardian whitework jacket.

As that outfit suggests, however, there is no misconception about her vault of an haute-couture wardrobe. I saw a small proportion of it scattered across Harlech's room: a silver-embroidered column of black taffeta, a few flawless tweed jackets and a chiffon sheath speckled with seed pearls, like dew. It's an utterly Harlech part of her Chanel contract that part of her wage includes a piece of custom-made haute couture from each collection. With neither the will nor way to take it back to Shropshire, Harlech keeps most of it chez Ritz. k

That's also a neat comment on the divided life Harlech leads: half on the Continent as the woman behind the man behind two of the most successful fashion houses in the world; the other half in deep rural seclusion on the Welsh borders. How does she square the two? "The head is still the same!" she states. "I'm not a schizophrenic, I don't change personality in the middle of the Channel."

That, however, is exactly what everyone expects. And Harlech hates to disappoint. A case in point: the first time we met she was in a geisha get-up to be photographed by Nick Knight for i-D magazine. The second time – again for a portrait sitting – she wheeled in a suitcase, wrapped herself in a vintage silk-and-velvet robe and Chanel couture lace blindfold and became something halfway between Nancy Cunard and Marlene Dietrich. It's more than dressing up; it speaks of the transformative fantasy of fashion – and it's not something you see every day.

It could balloon into pretentiousness, of course. But there's something surprisingly no-nonsense about Harlech. She's down-to-earth and incredibly funny, as far from the couture matriarch stereotype as possible. Few women would describe the hallowed ateliers of Chanel as "a lot of clucking, a bit like chickens. It just gets faster and faster and louder and louder without anything getting done. And I always feel like: 'Don't panic, Mr Mainwaring!'" Her role, an essential one for Lagerfeld, is to be the level-headed one, the calm amid the clucking.

Lady Amanda Harlech was born plain Amanda Grieve in Camden, north London. In fact, scratch the plain. "Where we lived was a nest of writers," she recalls. "Nick and Claire Tomalin, Jonathan Miller, Alan Bennett, VS Pritchett – as well as the Conrans. It was the most exciting place to be a kid. We all did plays and dressed up. It was fantastic." Her father, a solicitor, founded the charitable, artistic Jerwood Foundation, while her well-dressed mother allowed the young Amanda to indulge in her love of dressing-up. That liberal, art-filled upbringing led her down her first path, to Oxford University, where she planned to write a thesis on Henry James and moral bankruptcy. "My voyaging through literature led me to a writer who questioned every truth and intention," says Harlech. "And I find I'm doing the same at Chanel: questioning every surface, extracting the truth of what a designer is trying to articulate."

The leap from Henry James to haute couture is one that few would fathom – but Harlech vaulted it with ease. That said, her first experience of fashion was as a junior fashion editor at Harpers & Queen, where "we didn't work with the Chanels and the Saint Laurents. You had to do it with a T-shirt." Alongside her duties at Harpers, Harlech freelanced for London's junior style mafia – the inventive and arresting magazines that boomed in early 1980s London, i-D and The Face. "It was making something out of nothing, really, with scissors, pins and double-sided tape." Harlech's shoots from the period leap out: girls wrapped in brocades, tousled hair full of twigs and cobwebs like Miss Havisham.

Brocades? Twigs and cobwebs? Miss Havisham? It was only a matter of time before Harlech hooked up with John Galliano, who, in 1984, had just graduated from St Martins, unleashing his French Revolution-inspired Incroyables collection on a New Romantic-crazed London. How Amanda met John has since become a fashion fairy tale. "We sat and had tea, as the light thickened outside and the sky turned navy-blue," she recalls. "It was probably one in the morning when we finished. He brought his drawings, his paintings and his scraps of fabric, his story. Suddenly it was someone who was talking, speaking the same language as me. And my feelings were: 'I don't want to let him go, I can't possibly exist without him,' because he electrified everything that I had felt. Here was the stuff that I dreamt of."

So began a 12-year fashion love affair, as Harlech collaborated with Galliano every step of the way from original sketch to set-dressing. (It was her exquisite lace lingerie which hung on a washing line, "creating a mood" at Galliano's spring 1995 show – and was unceremoniously stolen.) Galliano himself remarked that Harlech was "more than a muse": indeed, years ahead of the now-standard "creative consultant" role allotted to many a stylist, Harlech was an essential cog in the Galliano machine.

"She really starts with me at touch base," said Galliano back in 1996. "Touch base? That sounds like a game of rounders!" shouts Harlech now, laughing. "John would say, 'I've got this idea for little pinstripe suits,' and I'd say, 'Well, they're little honcho girls and they're there in the bar, and they've rubbed up against the brick of the wall – and the brickwork made a mark at the back of their jacket.' That's how we'd work together." It sounds esoteric, until Harlech herself grounds it: "I'm interested in stories. I think I'm a bit of a pathfinder." Hence, Harlech's narratives with Galliano inspired the clothes they created. Take the old-fashion chestnut of X meeting Y (Ancient Egypt meeting hip-hop, for example); for Harlech and Galliano, X couldn't meet Y unless they knew when, where and why. "John created whole worlds for every woman, no, for every girl, boy, woman, man to explore," says Harlech, affectionately.

In 1986, amid the craziness of the Galliano years, Miss Amanda Grieve became Lady Amanda Harlech, marrying Francis David Ormsby-Gore, 6th Baron Harlech. It was their divorce just over a decade later that prompted a creative and professional separation with Galliano, as she shifted alliance to Lagerfeld, Chanel and a wage to support her family. "It was very different and I felt very isolated to begin with. At first take, I felt Chanel was incredibly ritualised, like a court, where everybody had their roles. We all curtsied and kissed at the same time: and if you don't kiss that person, you're considered very rude and you'll have your head chopped off. Now I understand more. Karl is incredibly warm, generous, hysterically funny, very challenging, extraordinarily bright, a maverick genius, never confrontational; it's as vivid in its way as it was with John."

Despite the regular wage, the question of what Lady Harlech actually does from day to day is tricky, because no two days are the same. In Paris, we meet in the afternoons because Harlech has been working through the night with Lagerfeld to accessorise the spring 2012 Chanel collection. Later that month, Harlech's BlackBerry messages reflect her path across Europe: shooting the Chanel campaign in the South of France with Lagerfeld and former Vogue Paris editor-in-chief Carine Roitfeld; to Rome for Fendi; back to Paris to prepare Chanel's pre-collection; and then to Shropshire for a few moments' respite.

Speaking to Harlech, it's easy to see why designers want her around: she's inspiring. Listening to her talk about anything from a book to a piece of music to a particular fashion collection fires you up. (She tries not to look at other shows, but is currently fixated on the "white drama" of Rei Kawakubo's spring Comme des Garçons collection.)

As to what fires up Harlech, that's simple: "Couture has a power that ready-to-wear can never have; the attention of les petites mains as they sew, all that love and belief goes into the cloth. That's what you feel when you wear it," she explains. Her eyes shine as she says this, but it's not the acquisitive glisten of the fickle fashion fraternity, but a true love.

"I'm anti-fashion. I really am," she adds. "I don't want people spending their money on It bags." At Chanel, home of the 2.55 handbag that launched 1,000 knock-offs, that seems nothing short of heresy. But for Harlech, fashion isn't about the easy answer. "I think the most destructive thing is fear: when people don't want to say what they think," she says. "The chorus of 'Oh, that's so beautiful' is very dangerous. I want to ask questions. I find the whole process of fashion a fascinating quest of discovery."