Sarah Jessica Parker wearing Yves Saint Laurent

By Natalie Glock 

One of the first It bags of the new season, the Yves Saint Laurent Besace bag, £1120, is already finding its way onto the arms of the A-list. Sarah Jessica Parker used her\'s at this year\'s Sundance Film Festival which she attended for the premiere of husband Matthew Broderick\'s new film Distinguished Capacity.

Julianne Moore wearing Yves Saint Laurent

As the guest of honour for Boucheron\'s 150^th anniversary party, Julianne Moore wore the much-admired Yves Saint Laurent grey marl bustier dress, £1050, straight from the Spring/Summer collection and the gorgeous new campaign featuring Kate Moss.

Sienna Miller wearing Yves Saint Laurent

Sienna proves that the grey, crocodile version of the Besace, £1120, is both chic and spacious, while out and about shopping in London.

Lou Doillon wearing Yves Saint Laurent

Celebrated for her unique brand of Parisian chic, Lou Doillon pairs her black Besace bag, £1120, with a grey oversized blazer and trilby and proves its versatility in the process.

Sarah Jessica Parker wearing Yves Saint Laurent

Filming this year\'s hotly anticipated Sex and the City movie, Sarah Jessica Parker was seen wearing head to toe new season Yves Saint Laurent. The light wool sleeveless jacket, £625, light wool wide trousers, £470 and grey silk top, £525, create the perfect crisp, clean lines for Spring.

Demi Moore wearing Yves Saint Laurent

Demi Moore shines in this Yves Saint Laurent rainbow printed silk dress, £700, from the recent cruise collection. The collection drew on artisan paint splashes of colour, a major trend for the coming season.   

Jessica Alba wearing Yves Saint Laurent

Dressing down for a shopping trip in LA, Jessica Alba\'s Besace bag, £1120, is the perfect companion.

Jennifer Aniston wearing Yves Saint Laurent

Opting for an all black ensemble, topped off with Yves Saint Laurent\'s Besace Bag, £1120, Jennifer Anniston steps out for the night in LA.