The 10 most powerful people in fashion

Mert Alas and Marcus Piggott, both 40

The photography duo have made waves with their glossy, digitally manipulated images. Their oeuvre spans shooting Lara Stone on a bed of violets for Tom Ford's Violet Blonde fragrance advert to depicting Kate Moss as David Bowie for French Vogue. An image by Alas and Piggott is the 21st-century equivalent of a court portrait, with subjects portrayed as glamorous, powerful and otherworldly - as stars including Angelina Jolie, Madonna and Rihanna can attest.

Sarah Andelman, 36 

Andelman is the creative director of Colette, the chic Paris concept store famed for championing new designers. Named after Andelman's mother, Colette Roussaux, the shop's quirky elements - such as a bar devoted to mineral water - were revolutionary for a designer boutique when it opened in 1997. Andelman also pioneered the idea of designer collaborations; recently she's persuaded Hermès to create special Colette scarves and Burberry to design a trench-coat with a Swarovski-studded collar.

Bernard Arnault, 63 

The luxury-goods mogul - and world's fourth richest man, with a net worth of £26 billion, according to Forbes - holds the reins of the LVMH empire, whose fashion brands number Louis Vuitton, Céline, Marc Jacobs and Givenchy. Arnault also holds a controlling share in Christian Dior. Skilled at granting often mercurial designers the space to create blockbuster brands, Arnault is said to be currently mulling over which designer will take over the role John Galliano abruptly left vacant at Dior.

Christopher Bailey, 40

Since he became chief creative officer of Burberry in 2001, Bailey has transformed the brand with his romantic, windswept and quintessentially British vision. Along with its former chief executive Rose Marie Bravo and her successor, Angela Ahrendts, Bailey has led the charge in turning Burberry into a global brand, which made record profits of £206.3 million in 2011. Bailey, who previously worked for Tom Ford at Gucci, has also heightened the label's cool quotient by recruiting young British stars such as Emma Watson, Eddie Redmayne and Felicity Jones to star in its campaigns.

Sarah Burton, 37 

When Alexander McQueen died in 2010, many doubted that the label could continue without its founding designer at the helm. However, his righthand woman, Sarah Burton, has proved the sceptics wrong. Since she became creative director, Burton has retained the label's design rigour while revealing a more feminine side to the house's creations. She stamped her mark on fashion history when she created the Duchess of Cambridge's wedding dress

The Duchess of Cambridge, 30 

Kate may not be the world's most adventurous dresser, but since her grand coming-out in an Alexander McQueen wedding dress, she's started to push the style envelope, wearing Erdem, McQueen and Roksanda Ilincic alongside her high-street staples. But no matter how fashion forward she is - or isn't - her style has struck a chord with women. Whatever Kate wears - from a Reiss cream dress to a Whistles silk blouse - often sells out within hours of her being snapped in it.

Samantha Cameron, 40 

Cameron was already a major figure in the fashion industry when her husband became Prime Minister, thanks to her role as creative director at the leather-goods label Smythson. But now as châtelaine of No 10, Cameron has wasted no time in promoting the industry. From opening up her home to fashion soirées, to sporting Erdem or Peter Pilotto on official occasions, Cameron's position as an ambassador for the British Fashion Council means homegrown style is now showcased at the most stately of occasions.

Katie Grand, 40 

This stylist is a master of subverting a celebrity's image. Under Grand's direction, Elizabeth Hurley donned fetishstyle ballet shoes for the cover of Pop magazine, while Abigail Clancy, the wife of the footballer Peter Crouch, went from tabloid fodder into a Bardot-esque siren for Love magazine, a title Grand founded. Acting as a consultant to Louis Vuitton, Grand has an often kooky, left-field take on luxury, meaning she is one of the most in-demand image-makers.

Marc Jacobs, 48 

Marc Jacobs is the creative force behind his eponymous label and the house of Louis Vuitton, two of the most watched collections of any season. Together with his business partner, Robert Duffy, an early fan of Jacob's student designs back in the 1980s, they have overseen the opening of a string of Marc Jacobs stores from Vietnam to Hawaii, and a revitalised Louis Vuitton. There Jacobs introduced ready-to- wear to the luxury luggage label and turned the notion of logos on its head by commissioning artists such as Takashi Murakami and Richard Prince to rework the iconic monogram.

Lulu Kennedy, 42 

As the founder of the Fashion East initiative to support young designers, Kennedy seeks out the rare sparkling jewels among a sea of young fashion graduates. It's thanks to Kennedy that designers such as Roksanda Ilincic, Jonathan Saunders and Richard Nicoll all got their start. In recognition of her talents Kennedy was named an MBE in this year's New Year Honours list.