LONDON, ENGLAND - OCTOBER 21:  Queen Elizabeth II and the Singapore President Tony Tan Keng Yam view a display of Singaporean items from the Royal Collection at Buckingham Palace 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  Anthony Devlin - WPA Pool/Getty Images)