Princess Diana, Prince Harry, Prince William and Prince Charles
Prince Charles agreed with Princess Diana to send Prince William to school because he could be “spoilt and difficult.” Pictured: Princess Diana, Prince Harry, Prince William and Prince Charles watch the parade march past as part of the commemorations of VJ Day on Aug. 19, 1995 in London. Getty Images/AFP/Stringer

Prince William used to be “spoilt and difficult” when he was a child.

Royal author Katie Nicholl revealed in her 2010 book “William and Harry” how life was for the Duke of Cambridge and Duke of Sussex during their younger years. She also shared how Princess Diana and Prince Charles finally agreed to send Prince William to nursery school.

Initially, Prince William was expected to be educated at home in keeping up with the royal tradition. However, the late Princess of Wales wished that both of her sons be mixed with other children their own age.

Prince Charles and Princess Diana’s marriage at that time was already heading south. However, the Prince of Wales agreed with his ex-wife that it was what’s best for Prince William.

“On this occasion, Charles was in agreement that William, who could be spoilt and difficult, would benefit from mixing with his peers,” Nicholl wrote.

When Prince William attended the Kensington nursery school, he was considered a terror and would reportedly anger his classmates by pushing his way to the front of refreshment queues. He also had a rough-and-tumble playground behavior that earned him the moniker “The Basher.”

Prince William would also get into fights due to his father, Prince Charles. The little Duke of Cambridge knew his princely status and was very proud that his dad is the future king.

“When he got into a scrap, a common event for the boisterous youngster, he would draw his play sword and challenge his opponent: ‘My daddy’s a real prince, and my daddy can beat up your daddy,’ he would shout,” Nicholl added.

Prince William and Prince Charles had a tricky relationship. According to reports, they weren’t that close due to his affair with Camilla Parker Bowles. In fact, at one point, Prince William lashed at Prince Charles for always arguing with his mom, Princess Diana, because it always ended with the People’s Princess crying.

The father and son also had an argument when Prince William decided to go backpacking for his gap year. The Prince of Wales was initially not supportive of his son’s plans. However, he eventually gave in and told Prince William that his gap year should be “vocational, educational and safe.”