Prince Harry and Prince Charles’ relationship when they were much younger was not as peaceful as it is now. The Duke of Sussex and his older brother were the ones most affected by the fallout of their parents’ marriage.

In the book “William And Catherine: Their Lives, Their Wedding,” royal author Andrew Morton detailed one of the heated arguments between Prince Charles and Prince Harry. He said that the latter was so affected by his parents’ unhappiness that he once told the future king that he hated him.

“Charles and Diana’s parental rivalry continued behind the closed doors of Kensington Palace,” Morton wrote. “Young Harry launched an attack on his father, ineffectually beating him on the legs with his fists,” he added.

Morton claimed that Prince Harry told Prince Charles that he hated him for making Princess Diana cry. Prince William, who is two years older than Prince Harry, already had the ability to understand what was going on between their parents.

The royal author said that the second in line to the throne was sensitive and a little shy. But on one occasion, he pushed tissues under the door to his mother’s bathroom when he heard the Princess of Wales crying.

But despite his maturity, Prince William also once lashed out at his dad for hurting Princess Diana. Katie Nicholl, a royal author, wrote in her book “William And Harry” how the Duke of Cambridge also told Prince Charles that he hated him for making his mom cry all the time. Prince William reportedly slammed the door in rage while shouting at his dad.

Prince Charles and Princess Diana were married for over a decade. In 1992, they publicly announced their decision to go their separate ways. Prince William and Prince Harry continued to live with their dad in the palace due to their royal status. Four years after their separation, Prince Charles and Princess Diana finalized their divorce.

Princess Diana, Prince Harry, Prince William and Prince Charles Prince Harry, Prince William and Prince Charles at a parade in the Mall, London, during V.J. Day commemorations, August 1994. Terry Fincher/Getty Images