And they continue to be admired for their fashion choices even when they're not in the limelight.
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Regular guests on the society wedding circuit, they consistently set the sartorial stakes high.
With their lustrous brunette locks and lovely warm smiles, the Middleton sisters are similar in many senses. But they differ in their colour preferences: Kate most often opts for neutrals and blues whilst Pippa is partial to vibrant reds, oranges and pinks.
Both are united in their love of the dress coat – perfect for the British weather and a chic, elegant finish.
Accessories are key to their outfits. Bold millinery creations colour coordinated with neat clutch bags and neutral coloured heels have become their trademark look.
Flick through our gallery of Kate and Pippa's best wedding guest outfits.
It's a little princess!