Catherine, Duchess of Cambridge waves to crowds as she arrives to attend the annual Order of the Garter Service at St George's Chapel, Windsor Castle in Windsor, England. She joined Camilla, Duchess of Cornwall in cheering on Prince William, Prince Charles, Prince Philip and Queen Elizabeth during the service. The Order of the Garter is the senior and oldest British Order of Chivalry, founded by Edward III in 1348. Membership in the order is limited to the sovereign, the Prince of Wales, and no more than twenty-four members.