They're both regarded as style icons.
And now Sienna Miller is to step into Victoria Beckham's territory by turning her hand to fashion design.
The Factory Girl actress, often seen in a pair of trademark skinny denims, has been asked to design her own line for Pepe Jeans.
According to the Daily Mirror, the deal is worth millions and an insider said:
"Even though she is ultra-skinny, her jeans will be made to flatter most sizes.
"The hope is she'll do for Pepe what Victoria Beckham has done for Rock & Republic.
"Sienna has become such a style icon in such a short space of time.
"She's been on the cover of Vogue, everyone knows who she is and this is the perfect time to do something like this.
"The jeans will be her own unique designs and the fact that she can model the clothes herself makes the whole project even more exciting."
Sienna signed a deal to become the "face and body" of Pepe Jeans in November 2005.
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