This morning, Kate participated in her first "Trooping of the Coulour.' She shared a carriage with Prince Harry, her mother-in-law Camilla Parker-Bowles, and Prince William's uncle Andrew.
The annual ceremony is held to recognize the birthday of the sovereign, though Queen Elizabeth turned 85 on April 21.
Kate watched with pride as her hubby took part in one of the world's greatest spectacles in honour of the queen.
The pomp wrapped up with The Royals reuniting on the balcony of Buckingham Palace.
Kate took center stage in a long double-breasted ivory dress coat with elegant, layered drapery detail running down the sides. It is by Alexander McQueen ($3,845 but no longer available). She wore a black Ark & Co straw and feather hat, simple studded earrings and had her hair loose.
Details about the cotton and wool blend pique coat from Net-a-Porter
'White cotton and wool-blend piqué coat with a softly pleated tiered Samurai skirt. Alexander McQueen coat has a short collar and lapels, accentuated padded shoulders, long sleeves with button-fastening cuffs, button fastenings through double-breasted front and is fully lined.'