Prince Charles and Princess Diana
Prince Charles and Princess Diana are pictured at an official event during their first royal Australian tour 1983 in Newcastle, Australia. Patrick Riviere/Getty Images

There’s never been a secret that Prince Charles and Princess Diana’s marriage was contentious at best, but a new documentary claims the future King of England had his doubts about a future with his wife even hours before their wedding.

According to the documentary, “Charles and Di: The truth Behind Their Wedding,” (via Express UK), several of Prince Charles’ friends expressed concerns before the wedding about the large age gap between him and his future bride. While he was already 32-years-old, his bride was just 19. However, his friends weren’t the only ones who were concerned, as royal expert Ingrid Seward revealed in the film that he also felt his wife was far too young, saying mere hours before their wedding that she “did not look old enough to be out of school, much less married,” even calling her a “child.”

“There was a whole group of Charles’ friends who saw this could be an absolute disaster,” Seward said. “She was like a high-school student and he was like a professor.”

However, while he admitted to being ‘terrified” of making a promise he would later regret in life, he still insisted he needed to marry her because it was the right thing to do as the heir to the throne, even though he knew they weren’t a suitable match.

“Prince Charles kept saying ‘I want to do right by my country. I want to do the right thing by my family,’” Seward recalled. “In his heart, I think he knew that they just had nothing in common.”

Sure enough, the couple’s marriage did not go well, despite it yielding their two sons, Prince William and Prince Harry. And while Diana reportedly always had some doubts about Charles’ relationship with Camilla Parker Bowles, her husband reportedly told her their marriage was basically over shortly after Harry’s birth.

“I could see the cracks in the marriage between Charles and Diana getting wider and wider, Diana confided in me that on the night Harry was born, she cried herself to sleep,” former butler Paul Burrell stated previously. “She says ‘I knew my marriage was over’ and the Prince told the Princess that his duty was now done. He had provided the country with an heir and a spare and he could now resume his relationship with Ms. Parker-Bowles.”

The affair did resume while the couple was still married and ultimately led to their separation in 1992 and eventual divorce in 1996, one year before Diana's tragic death in a car accident in Paris.