They’ve been together for nearly two decades and have weathered controversy including a recent bout of cheating rumors. However, Prince William and Kate Middleton’s commitment to their relationship was reportedly once tested by another member of the royal family.

According to “Game of Crowns” author Christopher Anderson, Camilla Parker Bowles, the Duchess of Cornwall, along with Prince Charles, once tried to drive a wedge between the Duke and Duchess of Cambridge. In a resurfaced interview with the Daily Beast (via Express UK), Anderson revealed that the couple’s 2007 break-up was because of his then step-mother.

“I have people telling me information about what’s going on behind the scenes—some on the record, some not—and I’ve always protected them and they’ve been wonderful,” he said at the time. “I was in London when the breakup [of William and Kate] occurred. I was shocked, completely stunned, everyone thought it was only a matter of time before William was going to ask Kate to marry him. And then people started telling me that Camilla was behind it.”

He went on to explain that at the time, the Duchess looked down on William’s girlfriend, who wasn’t a part of aristocratic circles, and who she felt wasn’t worthy of being a part of the family as a result.

“Camilla is a bit of a snob. She’s an aristocrat, she has always been moving in Royal circles,” he said, “She had always thought of herself as the heiress to Alice Keppel, her great-grandmother, who was the mistress of Edward VII. She was very proud of that connection, she boasted about that as a child and as an adult and that’s what she intended to be: part of the royal circle in the role of mistress to the future king, and then the king.”

“She did not look at Kate as someone who was worthy of joining the Royal Family,” he added. “Kate is the first working-class woman to be accepted into the Royal Family, She is descended from coal miners and he mother was a flight attendant. So for all of those reasons, Camilla never really felt that Kate Middleton as an individual and the Middleton family as a whole were going to be worthy of entering into the Royal Family.”

To ensure that Middleton didn’t join the family, Camilla reportedly started to whisper into her husband’s ear that it was time to force his son to decide what his future held and if Middleton had a place in it.

“I was told at the time of the breakup, and later on as well, that Camilla basically whispered in Charles’ ear that it was really time to make—to force—William to make a decision one way or the other,” Anderson said. “It has been since confirmed publicly that Charles did suggest to William that he either make a commitment to Kate or basically set her free, as it were. Now, his motives for doing that may have been pure but Camilla’s....not so much. She was the instigator of this.”

Of course, even though his grandparents also stepped in to tell him he needed to make a decision, Prince William went on to realize he wanted to be with his college sweetheart after all. They reconciled after a few months and went on to marry in 2011. They are now the parents of three children.