Prince Charles has reportedly been left out of Prince William and Prince Harry’s lives for years, and the reason may have to do with Princess Diana. A royal expert recently shared her thoughts about the royal family’s dynamic.

While speaking with Quest Red, royal expert Kate Williams said that Prince Charles is oftentimes left out when it comes to discussions on how he has impacted the lives of Prince William and Prince Harry. Even though Princess Diana has been dead for over two decades, her influence on her sons remains strong.

“William and Harry always talk so much about how they had a marvelous childhood,” Williams said. “Diana was always there for them, making life fun, taking them out on exciting places, spending time with them. I think there has been a degree of focus on Diana as a marvelous mother and perhaps Charles has been left out,” she added.

But even though much focus has been given to Princess Diana and her impact on her sons' life, Prince William and Prince Harry have also been vocal about how Prince Charles has supported them while growing up. The Duke of Cambridge and the Duke of Sussex have said that they owe a lot to their father because Prince Charles taught them so much.

Growing up, Prince Charles taught Prince William and Prince Harry how to pick litter from the streets. On the future king’s 70th birthday last year, the royal siblings said that they thought litter picking was normal because they did it regularly while they were in Norfolk.

At the end of the day, Prince William and Prince Harry certainly learned a lot from both of their parents. “What they are and what they’ll give to their children they taken from both parents,” Williams said.

However, their time with Princess Diana was short-lived. Princess Diana passed away on Aug. 31, 1997, following a fatal car crash in Paris. At that time, Prince Charles and Princess Diana have already been divorced for a year. The royal couple separated in 1992 after 11 years of marriage.

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