'Tension' brewing in the royal family: What's going on with Harry, Meghan, William and Kate?

There seems to be some tension within the royal family right now.

Following the announcement that Prince Harry and Duchess Meghan will be moving out of their two-bedroom home at Kensington Palace and into a 10-bedroom cottage at Windsor Castle, 20 minutes outside of London, reports have begun to spring up claiming that the real reason behind the move is due to "some tension" between the couple and Prince William and his wife Duchess Kate.

After all, news of their impending move out of Kensington Palace, which is where Will and Kate live with their three children, came after it was revealed that the brothers were also splitting their royal courts -- or, essentially separating their offices and teams -- due to their two different roles: Harry likely will never be king, while William is second-in-line to the throne.

"The brothers have leant on each other and looked after each other since their mother died," a source told The Sunday Times. "But now [that] they have their own families, they no longer rely on each other as before."

The split will reportedly come once Meghan gives birth to their first child next year. Royal historian Robert Lacey said that, though the separation makes sense on a practical level, it could also lead to increased rivalry between the brothers.

"It’s the nature of court to be rivalrous and competitive and that is a risk ahead," Lacey explained to The Daily Beast. "No matter how much the principals understand and trust each other, those around the principals, from private secretaries to press officers, will forever be jockeying for position. Let us hope it is healthy competition. It’s a hazard on the road ahead, but a manageable hazard."

Something else that could contribute to a growing rivalry between the brothers is Harry and Meghan's undeniably growing popularity around the globe. As Tom Sykes pointed out for The Daily Beast, for example, the Duke and Duchess of Sussex's reception during their recent trip to Australia "easily eclipses the enthusiasm with which William and Kate's 2014 trip to Australia -- even with crowd-pulling Prince George in tow -- [was] received."

The Daily Mail made sure to note, though, that Harry and William remain unusually close for royal brothers within the British royal family, and they've simply "both just grown up."

"They are rare in that they live together and work together, but there has been a stepping back," the outlet said. "They are still incredibly close, closer than most siblings, but now Harry has married and is about to become a father, so it's a good time for him to be planning his own future. There is no acrimony."

Royal author Christopher Andersen, who wrote "Diana's Boys," said that "the split really reflects the reality of the succession," but also posited that it's Meghan who's truly behind the decision.

"Harry and Meghan must carve out a role for themselves that is very different from that of William and Kate," Andersen told The Daily Beast. "I don't believe this move is a result of rivalry between Kate and Meghan, but I do think Meghan is pushing for Harry to step farther out of his brother's shadow as they prepare to start their own family."

"Do I think Meghan a lot to do with this decision? Yes, of course," he went on. "She wants her husband to have more freedom and autonomy and to run his own show -- all of which makes perfect sense as we move toward the reign of Charles III. She has urged Harry to take matters into his own hands, and he has wisely heeded her advice."

Meghan's involvement in the decision to formally split Harry and William's courts, as well as move to Windsor Castle, has naturally sparked speculation that there could also be a rift between she and Kate.

"Meghan and Kate have different interests and lead different lives," a source told ET of the pair, whose only joint outing together came back in July at the Ladies Final at Wimbledon, where the pair watched Meghan's friend, Serena Williams.

A Daily Mail source backed that up, saying that "they don't really get on."

Part of that tension could come from the fact that "the royal lifestyle and constraints are taking a time for Meghan to get used to." Meghan is "opinionated" and "very self-sufficient" and it's "taking a while for Meghan to get her head around" some of the expectations that come along with joining the royal family.

"While there are some tensions behind the scenes, Kate is pretty unflappable," a source told the outlet.

That being said, the decision to move to Frogmore Cottage at the secluded Windsor Castle seems to be a joint one made together by Meghan and Harry. The Daily Mail reported that "Harry simply doesn't want to bring his family up in such a visible manner as his brother," noting that George, Charlotte and Louis don't have very much privacy.

"The truth is that there simply isn't enough room at Kensington Palace for them," another source said. "Frogmore is just lovely and will be a beautiful place for the Sussexes to bring up their child. It's not that far from London. He or she will see plenty of their cousins. Harry and Meghan are incredibly happy and deservedly so."