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Happy Birthday, Kate Middleton!

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We've watched her every move with rapt attention over the past year and today, the Duchess of Cambridge celebrates the big 3-0.

Prince William's leading lady kicked off her birthday festivities last night at the London premiere of Steven Spielberg's latest flick War Horse, dressed in the gorgeous black lace Alice by Temperley dress at left. If you're jonesing to get the same look, we'd suggest the Esmeralda Georgette Mini Dress ($525) or Long Opal Dress ($510.30) by the same Brit label.

Rumors had circulated that Kate had an epic '80s-themed bash in the works for tonight, though more recent reports claim she wants to keep the event small and private. A shame, really—those Middletons are amazing party planners.

Still, no matter how she chooses to ring in her 30th, Kate's sure to do so in style. After all, from her turn in Alexander McQueen at her April nuptials to her handful of spot-on ensembles during her North American tour, the Duchess rarely puts a foot wrong, sartorially speaking. Happy birthday, Kate!

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