Queen's 90th birthday portrait released
  A photograph of the Queen and the Prince of Wales has been released to mark the end of her 90th birthday year.
  The photo shows the Queen with her son Prince Wales Chaeles in the White Drawing Room at Windsor Castle.
  Previously unpublished, it was taken before the final night of celebrations at the Royal Windsor Horse Show in May. Fashion photographer Nick Knight, who took the photo , said he had wanted to create something that showed "warmth, humanity... strength and tradition".
  The Queen, who last year became Britain's longest-regining monarch, turned 90 years old in April.
  In a speech at the event, the Queen had joked:"How I will feel if people are still singing Happy Birthday in December remains to be seen." About the newly-released portrait, Mr Knight said:"It was a great pleasure and an honour to photograph Her Majestry The Queen and HRH The Prince of Wales at Windsor Castle."