Prince Charles Felt Like Prince Philip "Pushed" Him Into Marrying Princess Diana, a Royal Biographer Says

• The tumultuous union between Prince Charles and Princess Diana may have seemed doomed from the start to some, but it was apparently Prince Philip who "pushed" his son to marry Diana.
• According to royal biographer Ingrid Seward, Charles proposed to Diana after his father gave him an ultimatum, saying, "You’ve either got to marry her or let her go....You can’t string her along."
• Seward says that Charles was "frightened of his father" and went along with marriage as a result.

Royal fans know that Prince Charles and Princess Diana's marriage was not a real-life fairytale. The couple shocked the world when they separated in 1992 and then ultimately divorced in 1996, but the writing was really on the wall from the beginning of their union.

Royal biographer Ingrid Seward, author of Prince Philip Revealed: A Man of His Century, explained to Us Weekly that Charles "felt he’d been very pushed into marrying" Diana—by none other than his own father, Prince Philip.

"He told some of his friends that he felt pressurized into marrying Diana because Philip said, 'You’ve either got to marry her or let her go. You can’t string a … young girl [along]. She’s only 19. You can’t string her along,'" Seward explained. "And all the press is saying, 'Oh, this is going to be the next queen.' You’ve got to take a stand and say that this is not going to work, or you marry her."

Apparently, the ultimatum pushed Charles to pop the question.

"Charles…he was frightened of his father and he probably thought, 'Well, OK. I’ll marry her if that’s what you want me to do.'"

And, if that's not enough royal tea to quench your thirst, Seward also revealed that Diana's friends actually wanted her to get together with Charles' younger brother, Prince Andrew.

"I think some of Diana’s friends thought that Andrew would be more fun for her than Charles, because he was very much her age and he was full of fun and everything else," Seward said. "But Diana wasn’t interested in Andrew. It was Charles she was interested in. She had been around the royal family ever since she was a little girl because her father and her family lived on the Sandringham Estate and her father was what’s called an inquiry to the queen. So, he sort of was in the royal household."