Princess Diana once gave Prince William a smack in public, which made the future king cry in front of his friends.

When the Duke of Cambridge was still young he was naughty and willful. This doesn’t make Princess Diana love her eldest son less, but she was not afraid to discipline him even in front of a crowd.

A newly resurfaced report revealed that Princess Diana gave the third-in-line to the throne a smack at his school on sports day when Prince William misbehaved. According royal correspondent Ashley Walton, Princess Diana lost her temper when Prince William ran away when she was about to leave after the event had ended. It turned out that Prince William wanted to play with his friends despite his mom’s disapproval.

“The seven-year-old Prince set off across a field to play with his sirens from London’s Wetherby School,” Walton wrote.

“Diana - clearly angry – dashed 100 yards, caught him by the arm and have him a firm smack on the bottom. William burst into tears. He was pushed back into the back of the royal car after a good telling off and driven back to Kensington Palace.”

Prince William and Princess Diana were very close. When the late Princess of Wales was stripped off his royal title, the third-in-line to the throne promised his mom that he would return it once he becomes the new king. Sadly, Princess Diana won’t be around when that time comes.

Meanwhile, Princess Diana and Prince William were reportedly not on great terms before the tragic accident that killed the People’s Princess. According to Vicky Ward, at the time, the Duke of Cambridge was starting to rebel against his mother, so he was very affected when Princess Diana passed away.

Also, both Prince William and Prince Harry admitted that they regretted their last phone call with Princess Diana. When their mom called, they were playing with their cousins and were in a rush to end the call to resume their playtime not knowing that it would be the last time that they would hear her voice.

Princess Diana, Prince Harry, Prince William and Prince Charles
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/Johnny Eggitt