She jazzed up her dress with a striking gold and black belt, gold earrings and Prada stilettos. Finishing off the look, she carried a gold and black evening purse.
The 30-year-old royal and her husband Prince William were the guests of honour at a reception at the Imperial War Museum to highlight the foundation's campaign to create new WWI galleries in time for the 2014 centenery of the conflict.
Interactive displays will feature letters and diaries which will explore the personal stories of those who lived and fought in the war.
The new galleries will re-display and enhance the museum's WWI collections for the benefit of future generations.
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It's a little princess!