(FILES) In this file photo taken on October 24, 2013 Britain's Prince Charles reacts to a comment as he meets guests during a reception in Clarence House, central London. - Trained from childhood to be king, Charles III has endured the longest wait for the throne in British history. He has spent virtually his entire life waiting to succeed his mother, Queen Elizabeth II, even as he took on more of her duties and responsibilities as she aged. But the late monarch's eldest son, 73, made the most of his record-breaking time as the longest-serving heir to the throne by forging his own path. (Photo by LEON NEAL / POOL / AFP)