Catherine, Duchess of Cambridge in her stylish self at Garter Day procession

Prince William and his new bride Kate Middleton joined other members of Britain's royal family for the historic Garter Day service on June 13, 2011 in Windsor, England.

The Duchess, wearing a dove-grey dress and coat by Katherine Hooker with a matching Philip Treacy head-piece stood next to the Duchess of Cornwall to watch the Knights and Ladies of the highest order of chivalry processed through the grounds of Windsor Castle ahead of the Order's annual service at St George's Chapel.

The Order, which was founded in 1348, is dedicated to the image and arms of St. George as England's patron saint, it is the pinnacle of the honours system in the United Kingdom. Membership is restricted to 24 Companions, in addition to the Queen, the Prince of Wales and a number of supernumerary knights and ladies, including members of the British and foreign royal families. Members of the Order wear a blue velvet cape and black velvet hat with white plumes during the annual gathering at Windsor.
New appointments for the Garter Day celebration were two Knights, bringing the total number of Garter knights to 23, Lord Phillips of Worth Matravers, the president of the Supremem Court, and Admiral Lord Boyce, a former head of the UK's Armed Force.

The newlywed first stunned Saturday at Trooping the Colour, Queen Elizabeth II's 85th birthday celebration, wearing a white cotton and wool-blend Alexander McQueen piqué coat and black hat by Sylvia Fletcher of James Lock and Co. Later that day, she joined newly single sister Pippa at a friend's wedding in Berkshire, England, sporting the same topper and a black-and-white Zara dress she'd worn out in 2007. Sunday, Catherine helped fête Prince Philip on his 90th birthday, wearing a bright blue coat she'd chosen for a friend's 2009 wedding, accessorized with her nude L.K. Bennett pumps and a Rachel Trevor-Morgan hat.

It seems the royal weekend was just a brief, stylish preview of what's to come on Catherine and William's North American tour.