Charles Spencer is opening up about his decision to only tell those in the publishing world ― and his wife — that he was writing a book about his late sister, Princess Diana.

“I took a conscious decision that this was very much my story, my responsibility,” Spencer said this week during an in-person conversation with Tina Brown in New York about his new book, “Swan Song: Diana, My Sister.”

“I thought if I told my family, my sisters, my nephews ― anyone else ― they would all have a view, as to content, and what I must include, and what I mustn’t,” he explained. “And also I didn’t want anyone to say to them, ‘You knew, why didn’t you say something about it?’”

Spencer said he told his relatives “on the day of the announcement before it went out.”

“So they got almost no warning, and I think it was a big surprise,” he added.

Spencer said that he also “took two views on this” when deciding whether to tell those close to him.

“I explained it to them; I was going to surprise you either way. If I told you back in January, then you’d have been surprised and want to either contribute or whatever or edit or something. Or else I just do it this way and there we are.”

Brown asked Spencer what his nephews, Prince William and Prince Harry, thought of the news.

“In respect of their privacy, I won’t sort of say what was said, but it was OK, you know?” he said. “I mean, I think they’re probably used to me, to sort of doing my own thing, and I made it absolutely clear to them ― I haven’t compromised either of your privacy at all.”

Brown then pointed out that there’s one person who certainly isn’t “thrilled” with the book ― King Charles.

In explosive excerpts published prior to the publication of Spencer’s book, the earl specifically recalled one damning conversation he says he had with then-Prince Charles.

Spencer alleged that Charles called him to talk about the death of Diana, and at one point reportedly became enraged and said, “We’ll forget her soon enough!”

Buckingham Palace issued a rare statement in response to the claim, telling HuffPost shortly after the excerpt was published: “While we do not comment on books as a matter of principle, His Majesty is mindful that the pain of fraternal grief can cloud reason, affect judgment and color memory in ways others do not recognize, even many years after such a loss.”

By entering your email and clicking Sign Up, you're agreeing to let us send you customized marketing messages about us and our advertising partners. You are also agreeing to our Terms of Service and Privacy Policy.