Prince Philip and Princess Diana
Prince Philip and Princess Diana had a complex relationship, according to a royal biographer. Pictured: Prince Philip, Prince Charles, Queen Mother, Princess Diana and Queen Elizabeth II after Prince William’s christening at Buckingham Palace on Aug. 4, 1982. Getty Images/PA

Prince Philip and Princess Diana had a complex relationship.

The Duke of Edinburgh and the People’s Princess were harsh at each other in certain situations. But there were also times when they were very warm toward each other.

According to Tina Brown in her 2007 book “The Diana Chronicles,” the 97-year-old senior royal was “angry, raging and unpleasant” to the People’s Princess after learning her and Prince Charles’ separation.

There was also a time when Princess Diana felt bad with Prince Philip for tolerating Prince Charles and Camilla Parker Bowles’ affair. Princess Diana revealed in her voice coach how the Duke of Edinburgh told the Prince of Wales to marry her and reunite with Camilla if their marriage doesn’t work out after five years. That was exactly what happened.

Princess Diana didn’t also like Prince Philip’s tough love letters. “Charles, Philip told her, had ‘made a considerable sacrifice’ in cutting ties with Camilla, and the Princess ‘had not appreciated what he had done,’” Brown wrote.

One time, Prince Philip also offended Princess Diana when he asked her this question: “Can you honestly look into your heart and say that Charles’ relationship with Camilla has nothing to do with your behaviour towards him in your marriage?”

Although Princess Diana and Prince Philip had those encounters, the duke was more supportive of Princess Diana compared to Camilla. He wrote his daughter-in-law a number of personal letters. Also, in one of his letters, he called his own son, Prince Charles, “silly” for leaving Princess Diana for the Duchess of Cornwall.

“I cannot imagine anyone in their right mind leaving you for Camilla,” Prince Philip wrote which “gladdened Diana’s heart,” according to Brown. Prince Philip also signed one of his letters to Princess Diana with “With fondest love - Pa.”

When Princess Diana died, Prince Philip was among the men who walked behind her coffin during her funeral service. The duke joined Prince William, Prince Harry, Prince Charles and Earl Spencer.

According to Ingrid Seward, Prince William didn’t want to do it. The royals persuade him to join but the Duke of Cambridge gave them a condition: he would only do it if Prince Philip would join them.

Prince Harry also revealed that he didn’t choose to walk behind Princess Diana’s coffin. The Duke of Sussex told Newsweek that it was not easy for a child to walk a long way behind his mother’s coffin with millions of people watching.