Prince Charles has been preparing for his role as King all his wife. And he has received proper training from Queen Elizabeth II.

But it has now been revealed that Her Majesty isn’t the biggest influence in the heir to the throne’s life. The title wasn’t also given to his ex-wife, Princess Diana or his current wife, Camilla Parker Bowles.

While speaking with Express, body language expert Judi James said that the biggest influence in the dad of two’s life is his feisty only sister, Princess Anne.

“Charles had a very strong mother figure in his life who – although often being seen as rather remote and hands-off – was also the equivalent of his boss in terms of his royal ‘career,’” James said. Prince Charles and Princess Anne grew up under the care of their nannies because their parents were very busy.

As such, Princess Anne became a great influence on Prince Charles. And since Prince Charles’ dad, Prince Philip, was very strong and dominant, he also learned how to be strong and dominant in his own way.

“These influences seem to be etched on his facial expression and body language traits, emerging as signals of anxiety, like his steepled brows and his self-comfort hand rituals. But he also shows symptoms of a rather laid-back sense of humor too, with his asymmetric smile and often quite piercing eye gaze,” James said.

Meanwhile, James also talked about Prince Charles’ body language when he accompanied the Queen to the State Opening of Parliament. According to the body language, the heir to the throne’s demeanor was bordering on distress.

James also noted how Prince Charles’ brows and turned-down mouth gave him an expression of concern. And if his demeanor will be compared to Prince William, the dad of two is definitely more anxious than his son when they are out in public.

Her Majesty’s body language, on the other hand, conveyed a slew of emotions. Royal fans claimed that she seemed furious while at the event.

Princess Anne, Prince Charles
Pictured: Princess Anne, Prince Charles arrive for the Garter service at St George's chapel at Windsor castle, 13 June 2005. Getty Images/Odd Andersen/AFP