Exclusive: Charles Spencer Shares Why He Thinks Princess Diana Would’ve Loved One Way Prince William Shook Up Royal Tradition

Prince William and Prince Harry were only 15 and 12 when their mother died, but Princess Diana’s brother, Charles Spencer, tells Marie Claire that he sees his late sister’s influence on both of his nephews.

Earl Spencer, whose new book, Swan Song: Diana, My Sister, was released on September 22, shares that like Princess Diana, William and Harry display an “independence of thought” from the rest of their family.

“Times have changed,” Spencer says, adding he thinks it’s “huge progress” that Prince William and Princess Kate spent some of their Christmases with the Middleton family before he was the Prince of Wales.

“You know, it really hurt Diana, family Christmases were a very, very big deal for us growing up, whether they're with my father or mother, and then we did those alternately,” Spencer shares. Instead of seeing her family, Princess Diana wasn’t given a choice other than to spend the holidays with the Royal Family—an experience she hated.

Spencer continues that it was sad for his family to have their Christmas celebrations continue on without Diana, especially since she “was only 20 when she got married.”

He says it “just seemed so thoughtless” that his sister could never celebrate Christmas with the Spencers, praising William for spending holidays with his in-laws when he could. “I think that would be the sort of independent, logical thinking that Diana would have imparted into her sons,” Spencer shares.

As for Prince Harry, Earl Spencer says his nephew has inherited one of Diana’s best qualities. “It’s very interesting to me to watch Harry with people,” he tells Marie Claire. After “chatting with Elton John at a charity event,” Spencer says they both agreed that other than Diana, Harry was the only high-profile person they’ve seen “instantly connect on sort of a joyful level with members of the public."

“He also has this incredible connection with kids, which, you know, you can’t fake that,” Spencer adds of the Duke of Sussex, praising the “incredibly easy way” he relates to children, just like his mother.

Spencer has made his feelings on King Charles known in the book (and in numerous interviews), but when asked what type of King he thinks Prince William will be, Spencer takes a moment to consider it.

"That's such a tricky question," he says after a beat. "I'm not avoiding the question, but I'm sure he'll be a successful one. I've never thought about it, to be honest."

Touching on how the Prince of Wales has been open about wanting to make some changes to the monarchy, Spencer adds that he thinks his nephew will combine "the obvious duty of the role with a thoughtful take on what is expected in the modern world from a monarch."

Despite William's potential plans for modernization, Spencer notes that his nephew "would never impose any of those thoughts on the world when his father is the monarch," adding, "I'm sure it will be very considered when the time comes for him to take over."