Britain's Princess Margaret (L) and her older sister, Britain's future Queen Elizabeth II (R) in 1933. (File/AFP)

Queen Elizabeth, the former Duchess of York (R), King George VI, and their daughters Princess Elizabeth (C) and Princess Margaret pose on May 12, 1937 in London after the Coronation of Duke of York. (File/AFP)

Queen Elizabeth the Queen Mother, Princess Elizabeth (future Queen Elizabeth II), Princess Margaret and the King George VI at Buckingham Palace. (File/AFP)

Members of the British Royal family and guests pose around Princess Elizabeth (future Queen Elizabeth II) and Philip, Duke of Edinburgh (future Prince Philip) at their wedding. (File/AFP)

Britain's Queen Elizabeth II and Britain's Prince Philip, Duke of Edinburgh wave to the crowd after their wedding. (File/AFP)

King George VI, Princess Elizabeth's father, Queen Mary, mother of the King and Princess Elizabeth during the christening of Prince Charles. (File/AFP)

Britain's Queen Elizabeth II sits in Westminster Abbey on June 2, 1953 in London during her coronation. (File/AFP)

Britain's Queen Elizabeth II and Britain's Prince Philip, Duke of Edinburgh wave to the crowd from Buckingham Palace following her coronation. (File/AFP)

Queen Elizabeth II receives from a well-wisher floral tributes for Diana, Princess of Wales at St. James's Palace in London on Sept. 5, 1997. (File/AFP)

Prince Charles (R), his son Prince William (back L) and Queen Elizabeth II watch the coffin containing Queen Elizabeth the Queen Mother leave Westminster Abbey, in London, before 09 April 2002. (AFP/FILE)

Queen Elizabeth II (R) and Kate Middleton, The Duchess of Cambridge, speak as they visit De Montfort University, in Leicester, on March 8, 2012 as she started her Diamond Jubilee celebrations. (FILE/AFP)

Queen Elizabeth, Prince Charles, and members of the royal family celebrate Queen’s Birthday, trooping color. (File/Shutterstock)

Prince Philip and Queen Elizabeth in London June for the Trooping the Color parade. (File/Shutterstock)

Britain's Queen Elizabeth II greets Britain's Prime Minister Boris Johnson during an audience at Buckingham Palace in central London. (File/AFP)

Britain's Queen Elizabeth II stands on the Balcony of Buckingham Palace as the troops march past as part of Queen Elizabeth II's Platinum Jubilee celebrations, in London. (File/AFP)