Princess Diana once gave her eldest son, Prince William a surprising nickname.

In an article for Vanity Fair, American journalist Christopher Andersen revealed how Princess Diana came up with her son’s nickname using the letters “DDG.”

The three letters stand for drop-dead gorgeous, and the Princess of Wales thought it was fitting because Prince William is handsome. In fact, the late royal also saw similarities between the appearance of the Duke of Cambridge and the late US President John F. Kennedy.

“Like his closest counterpart in America, the late John Kennedy Jr., Hollywood-handsome William often seems to resemble a flawless actor who might be chosen to portray him on-screen rather than the genuine article. Diana, who was so keenly aware of her son's cover-boy potential that she dubbed him D.D.G. (for Drop Dead Gorgeous), also saw the parallels with young Kennedy,” Andersen wrote.

The journalist also revealed that just months before Princess Diana’s death, she told her friends that she hopes Prince William will become as media savvy as Kennedy. She also hoped for the future king to be able to handle things as well as Kennedy did when he was still alive.

Meanwhile, Princess Diana also had other nicknames for Prince William. When he was much younger, Princess Diana called her son Wombat. Prince William’s other nicknames include William the terrible, the basher, and mini-tornado by his mother.

The Princess of Wales also had a unique nickname for her youngest son, Prince Harry.

In the documentary “William & Harry: Princes At War,” royal author Robert Jobson revealed that the late royal used to call her son good King Harry or GKH.

When the Duke of Sussex was still very young, he expressed his desire to become the future king of Britain.

During one of his feuds with Prince William, the latter said that he doesn’t want to be king. Prince Harry responded by saying that he would gladly take over the role if possible.

Upon hearing this, Princess Diana gave Prince Harry the nickname good King Harry because she thinks he is more suited for the top job. However, Princess Diana was well aware that Prince William is the one who’s destined to take over the throne.

Princess Diana passed away on Aug. 31, 1997. At that time, Prince William and Prince Harry were still very young. As such, the royal siblings grew up without the guidance and love of their mother.