Prince Charles, the heir to the throne, had the unlikely support of his father, Prince Philip, the Duke of Edinburgh, at a most turbulent time in his life. While dealing with his rocky marriage to Princess Diana, it was his dad who was actually rooting for him to pull it through.
In the book "Harry: Conversations with the Prince," author Angela Levin revealed that Prince Philip saw the anguish and guilt of Prince Charles over his failed marriage to the People's Princess. Apparently, Prince Charles was so consumed with unhappiness because he thought he let down his mother, Queen Elizabeth, and the British people.
Prince Charles apparently found solace in the letter Prince Philip wrote to him. While his father was normally critical of him growing up, the Duke of Edinburg was sympathetic and understanding of his time this time around.
Prince Philip apparently made it known to his son that he had the "fortitude of a saint" for enduring a marriage to the Princess Diana. She was apparently a difficult person to be with but most of the people blamed Prince Charles for their marriage's failure because of his affair with Camilla.
Prior to their divorce, Prince Philip apparently also wrote Princess Diana. In it, he conceded to Prince William and Princess Harry's mother that his grown son might have done a silly thing to leave her for his mistress. He also signed the letters "with fondest love, Pa."
According to The Telegraph, Prince Philip tried to save Prince Charles and Princess Diana's marriage. The duke also laid it out honestly for Princess Diana and told her that she might have driven Prince Charles out of their marriage for her bulimia, which affected her behavior.
The correspondence between Prince Philip and Princess Diana apparently unleashed many outspoken issues about the royal family. It was a no-holds barred attempt, where Prince Philip didn't mince his words but also offered advice for his daughter-in-law.
It came to a point when their letters for each other became shorter and shorter, at which instance Princess Diana told Prince Philip that he may have understood her better than most, including Prince Charles. She reportedly kept these letters intact and copied some of it for her confidantes in order to preserve the truth of her story.
Prince Charles and Princess Diana lived separately for years and vowed they will not divorce, with respects to the crown. However, Queen Elizabeth ordered them to do so because their separation was causing more problems for the royals.
