LONDON, ENGLAND - JULY 02:   (EDITORIAL USE ONLY) Catherine, Duchess of Cambridge holds Prince George as he and Prince William, Duke of Cambridge's look on while visiting the Sensational Butterflies exhibition at the Natural History Museum on July 2, 2014 in London, England. The family released the photo ahead of the first birthday of Prince George on July 22.  (Photo by John Stillwell - WPA Pool/Getty Images)