In the decades to come, when academics and biographers come to write the royal history of 2019 and 2020, it will be the period when the "spares", inadvertently, came perilously close to bringing the house of Windsor undone.
The years will be forever defined by Prince Andrew's fall from grace over his friendship with convicted sex offender Jeffrey Epstein, along with Prince Harry and Meghan's painful, very public exit from royal life.
They were two events, wholly independent of one another, one driven by the events of the past and the other by a desire to carve out a different sort of future, news.com.au reported.
Now, Nigel Cawthorne, the author of a new book about Prince Andrew has alleged that there was in fact a "connection" between these crises and claims Prince Charles and Prince William used the Duke of York's car crash BBC interview last year to stage what amounted to a "silent coup" against Prince Harry.
Here's the background. For a number of years, Prince Charles has ardently supported the notion of a vastly slimmed down monarchy. For example, at last year's Trooping the Colour 44 members of the extended house of Windsor took to the Buckingham Palace's balcony. (Even ardent monarchists would be hard pressed to name half of them.)
It has also been reported there are more than a hundred members of the vast Windsor clan who live in grace-and-favour homes in various palaces, receive funding via the Sovereign Grant or receive official protection.
Charles' vision for a far leaner monarchy was on full display in 2012 when only his wife, sons and daughter-in-law joined Her Majesty on the palace balcony to mark the end of the Queen's Diamond Jubilee celebrations.
Fast forward to November 2019, when Prince Andrew sat down with Panorama's Emily Maitlis for a nearly hour-long interview about his relationship with Epstein conducted in the gilt-edged bosom of Buckingham Palace.
For 50-odd minutes, he offered up a series of bizarre explanations for the events in question
Within days of the gross PR miscalculation, he was forced to step back as a working member of the royal family.
Around the same time, there was another royal story bubbling to the surface. Only the month before, in October 2019, another TV documentary about the royal family had made global waves, in which Harry and Meghan, the Duke and Duchess of Sussex spoke about the personal toll that royal life was taking on their young family.
"The Charles-William faction at the palace is in seemingly unstoppable ascendant," Cawthorne has told the Daily Mail. "The two heirs found common cause that the unwieldy monarchy has to be pruned, starting with their independently-minded brothers Andrew and Harry."
"The starting shot was Andrew's BBC Newsnight interview. The Charles faction at the palace clearly saw that it created the opportunity of removing not only Andrew, but also Harry from royal engagements."
In January 2020, the stage was allegedly set: Two spares whose personal predicaments were dominating global headlines and two future kings who allegedly saw an opportunity to act.
On January 7, The Sun broke the sensational news that Harry and Meghan felt "sidelined" by the royal family and were considering moving to Canada.
In his book, Cawthorne writes: "The palace had known for months, as well, about the Sussexes' desire to step back from their roles as senior royals and were secretly negotiating the implications of such a move with the couple.
"Was it a coincidence that, shortly after the Newsnight interview spectacularly misfired, the emigration of Harry and Meghan, his wife of African-American descent, to Canada was leaked?"
"In the modern history of Buckingham Palace it was probably one of the most stunning silent coups," Cawthorne said this week.
While the book about Prince Andrew is out now in Australia, it is yet to be published in the UK. The Daily Mail reports they understand "that some of the central claims in Cawthorne's forthcoming book are disputed".
There are a few sticking points with Crawthorne's thesis. While Andrew might have been something of a thorn in the side of Charles since the '80s when the dashing navy captain's popularity far eclipsed his stuffy own, the Princes of Wales' "slimmed down" model always included both of his sons.
In 2012, when only an austere six HRHs took to the Buckingham Palace balcony, there was Prince Harry, smiling and joking with his family.
Similarly, would Charles and William, as canny future kings, have really wanted to see The Firm's two most charismatic frontline working members dramatically sidelined? (Not to mention leaving the remaining HRHs with even greater responsibility to shore up the monarchy's image and to contend with potentially increased workloads?)
I struggle with the idea that ousting Harry and Meghan in any way furthered their interests.
Likewise, I would think that Charles and William are perceptive enough that they would have foreseen that any drama-laden Sussex exit would only result in a global media storm and leave a lingering funk of scandal and rancour over the palace.
This week, Prince William visited an Oxford hospital fighting COVID-19. The idea of him and Charles, politicking and plotting behind palace gates, runs dramatically counter to this image of him as a thoughtful, focused future leader that the palace is clearly working so hard to establish.
Wherever the truth lies, Cawthorne's book will lend credence to the claims of collusion between various royal blocs who allegedly sought to contain the wayward, attention-hogging Sussexes.
If there is any kernel of truth to Crawthorne's account, it will add considerable sway to the reports that Meghan feared they was a "conspiracy" against her, as a friend of hers told The Times in May.
One thing seems certain. No matter where in the world the Sussexes go, and how many games of golf Andrew plays far away from the cameras, this particular chapter in royal history is far from over.
Daniela Elser is a royal expert and writer with more than 15 years experience working with a number of Australia's leading media titles.