LONDON, ENGLAND - OCTOBER 21: Britain's Catherine, Duchess of Cambridge (L) and Prince William, Duke of Cambridge (R) attend the ceremonial welcome ceremony for Singapore's President Tony Tan Keng Yam at the start of a state visit at Horse Guards Parade on October 21, 2014 in London, England.  The President is at the beginning of his four day stay during which he will hold a bilateral meeting with Prime Minister David Cameron. (Photo by Leon Neal - WPA Pool/Getty Images)