09/02/2017 04:39 GMT | Updated 09/02/2018 05:12 GMT

Inside Dior

Lucas Jackson / Reuters

Charlize Theron is not to be messed with. My time is strictly limited and there are more primpers and minders than the entourage of your average head of state. As she settles in her fabulous frock - Dior, of course - worries that a pin might be pricking her are dismissed and our little chat begins.

This bemusing ritual is standard procedure for an interview with a Hollywood star, but we catch more revealing moments later when our privileged access - filming an observational documentary - pays dividends. Charlize is guest of honour at tonight's banquet to celebrate the restoration of Christian Dior's mansion in the South of France and is, of course, placed on the right of the firm's owner, Bernard Arnault. He is the richest man in France (his empire, of which Dior is a mere part, made profits of six billion Euros last year). Just before the hors d'oeuvres (delicious, by the way), I notice her take a pink rose from the table and hold it under M Arnault's nose. A star knows instinctively what to offer the man who has everything.

The rose and jasmine harvests in the rolling hills around Grasse make a stunning picture. Francois Demachy - the 'nose', the man on whose nasal instincts the success of Dior Parfum depends - gives us access to his high-security lab. This is an ultra-secretive, cut-throat business. A kilo of Jasmine essence is worth twice its equivalent in gold. You can't patent the formula of a successful perfume, so when he lets us film one - a sheet of paper clearly marked 'confidential' - I make sure some if it is out of focus...

Christian Dior was a savvy businessman. After his first couture collection hit the headlines in 1947 with the so-called 'New Look', his empire was launched - and he understood that the brand which bears his name could capitalise on its appeal and branch out into luxury perfumes, cosmetics, accessories. Since his death - a mere ten years later - the company has cleverly exploited his legacy and grown to the massive billion-dollar business it is today. But the ateliers - workshops in the attics of Dior's HQ on the posh Avenue Montaigne Paris - still house the women and men (the 'petites mains') who hand-make each wildly expensive item of haute couture.

Catherine Riviere is the elegant woman - of indeterminate age - who runs Dior Haute Couture. Each ravishing creation is cut for the model who will launch it on the catwalk. Clients will have theirs individually made, no matter what their size. 'Poor things, they have to be dressed!' says Catherine, briskly, revealing to me the 'casts' of clients' torsos lining the shelves - 'as you see, some have big breasts, some no breasts, some no waists!'

Florence - or 'Flo' - is in charge of the dress-making workshop - and while famous designers might come and go, they all understand that there's nothing that Flo doesn't know about her craft. In the mad rush to get all the model fittings done by show time, Flo is no-nonsense. She goes up to someone she's never met and with hardly a 'bonjour' grabs her décolleté and gives it a yank upwards. 'No, this needs adjustment' she announces. The model is of course unperturbed.

Flo is sanguine about the whole crazy business. She clearly loves her work, but when I ask her whether she fancies wearing any of the clothes she makes, she fires back 'I make dresses for Princesses, Ladies - I wouldn't want to wear one of these - No, no, not for me - I'm happy as I am - I'm a woman of the earth!'

We film the Haute Couture show not normally seen - put on specially for the clients, not the press. Despite the shape of some of the 'casts' we filmed in the atelier, the Duchess of Windsor's famous phrase, 'never too rich, never too thin' seems apposite. An insight into the way the world's economy is moving: a large proportion of the guests are from China. Before and after, the champagne flows and Catherine Riviere woos them all charmingly.

We follow the appointment and arrival of the first female Creative Director in Dior's history - the Italian, Maria Grazia Chiuri. During the frenzied tension of the build up to her first show, she chuckles and jokes with me as she puts the final touches to her elegant and witty outfits. We sneakily film as the glacial Empress of fashion herself, Anna Wintour, arrives for a special private preview. (Ms Wintour thaws, and even accepts a proffered chocolate, though there's no evidence that she actually ate it).

Maria Grazia's daughter Rachele comes to Paris to give Mama support. The Rodin Museum is transformed - at heaven knows what cost - for the show that will last all of ten minutes. In a touching scene as mother and daughter are limo'd from the final lighting rehearsal back to the fittings, Maria Grazia puts her head on Rachele's shoulder and sighs. As she says, 'It's not easy, Dior!'

Michael Waldman, Director, Inside Dior. The two-part series Inside Dior is on More4, Thursday 9 and 16 February at 9pm.