Britain's Prince Philip, Duke of Edinburgh (L) and Britain's Prince William, Duke of Cambridge (R) accompany Britain's Queen Elizabeth II (not pictured) as she officially unveils the Windsor Greys statue in Windsor on March 31, 2014. The statue marks 60 years of the queen's Coronation in 2013 and the role played by Windsor Grey horses in the ceremonial life of the royal family. Windsor Grey horses have been drawing the carriages of successive monarchs since Queen Victoria. AFP PHOTO/POOL/ARTHUR EDWARDS        (Photo credit should read ARTHUR EDWARDS/AFP/Getty Images)