Shortly after Prince William and Princess Kate were married, Prince Harry was often their "third wheel" at royal functions.

For a while, the arrangement worked well, and Harry got along well with his brother and sister-in-law, but according to sources who spoke to the Telegraph, he felt like a "gooseberry" being forced to follow them around at events.

"They had no real disagreements [at the time]," one source explained.

"But there were philosophical differences in the way things were done."

"William was more reserved about what to say to the media and worried about sharing too much in a way that would put pressure on others."

Apparently, the plan was for Prince Harry to stay with the then-Cambridges until Queen Elizabeth's death, at which point they would separate into two houses, but another source called this idea "misguided."

"It puts too much pressure on their relationship. It's not healthy."

The Telegraph's source explained that William was a bit of a father figure to Harry, often giving him advice.

However, by the time Meghan Markle came into Harry's life, "Harry was fed up with the dynamic that had developed with his brother," one source said.

One source added, "A lot of this predates Meghan. But it's safe to say that her arrival changed things."

Meghan Markle was expected to turn the royal trio into a royal quartet, but "it soon became clear that their styles were too different," one aide said.

It was then that the Cambridges and Sussexes were separated.

"A divorce was in progress, but the terms had not been finalized," said one source.

"Behind the scenes, it was like, 'We need to put these brothers back together.

"They were still talking, but it was tense."

Then, of course, came the royal exit. At this point, the relationship between Prince William and Prince Harry seemed to be deteriorating at a rapid pace, despite occasional reports of an impending reconciliation.

The rest, as they say, is history... Until Thursday's Netflix release added another piece to the puzzle.