LONDON, UNITED KINGDOM - OCTOBER 21: (EMBARGOED FOR PUBLICATION IN UK NEWSPAPERS UNTIL 48 HOURS AFTER CREATE DATE AND TIME) Catherine, Duchess of Cambridge and Prince William, Duke of Cambridge attend the ceremonial welcome 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 Max Mumby/Indigo/Getty Images)