How King Charles Secured Camilla's Queen Consort Title Before Queen Elizabeth's Death

King Charles made a secret deal with Queen Elizabeth amid the Prince Andrew-Jeffrey Epstein scandal that secured Camila's Queen Consort title, according to a royal expert.

During an interview with Us Weekly, Christopher Andersen, the author of "The King: The Life of King Charles II," said Charles stepped up to distance the royal family from Prince Andrew.

The Duke of York was accused of sexual abuse, stepped away from his royal duties and was eventually stripped of his royal patronages and military titles.

In February, Prince Andrew settled a sexual assault lawsuit. Although the financial terms weren't disclosed, it is believed that Queen Elizabeth "was going to dip into her personal pocket" to pay the fee.

"Now, that meant, really — because Charles just was going to be the heir — that this was also money that would've come to him eventually," Andersen said.

While "Charles could have objected," he used the timing of the settlement to his advantage.

Since the court proceedings occurred at the beginning of the queen's Platinum Jubilee, he saw the event as the "perfect time" to "endorse Camilla as a Queen Consort."

"And so in a kind of an unspoken implicit deal, this was the tradeoff," Andersen explained.

"And that announcement was made...it was very abrupt, you may recall, it was something [that took] everybody by surprise...she was so against Camilla ever becoming queen for decades and decades, that it, it was a complete about-face, [and] that I think [it] shocked a lot of people."

Camilla received the title of Queen Consort on Sept. 8, the day of Queen Elizabeth's death.

Andersen told Entertainment Tonight that King Charles was "one of the most eccentric sovereigns Great Britain has ever had."

Andersen claimed Charles "travels with a custom-made toilet seat" and allegedly brings his chef when he eats at other people's homes.

King Charles also shares idiosyncrasies with other royals. "I think one of the funniest quirks -- a number of royals have this, the queen had it as well -- they don't like square ice cubes," Andersen said.

"They carry around ice cube trays, have them brought with them wherever they go because they don't like the clinking sound that square cubes make."

However, not all of Charles' eccentricities are considered humorous. Andersen claimed the monarch is "very moody, very temperamental."

"He has a volcanic temper, in fact," Andersen said. "He's very capable of flying into rages."

Andersen believes King Charles' behavior is a result of his strained relationship with his parents, the late Queen Elizabeth and Prince Philip.