The Duchess of Edinburgh has emerged as King Charles' 'secret weapon' within the Royal Family, becoming one of the most respected and admired figures in the monarchy today, according to a royal expert.

King Charles, Queen Camilla and other members of the royal family participated in the Christmas walk to St. Mary Magdalene Church at Sandringham in Norfolk.

As the health of the Royal Family appeared to be improving - with the King returning from a successful long-haul trip to Australia and Samoa and Kate announcing her chemotherapy had concluded - the Queen was struck by a nasty chest infection, which was later diagnosed as pneumonia.