On June 21, 1969, the royal family made UK history when a 90-minute documentary imaginatively called Royal Family aired.
In a wholly unprecedented move, the Queen had allowed cameras inside Buckingham Palace, Windsor Castle and Balmoral with the BBC's capturing 75 days of shooting in 172 locations. It showed such dramatic moments (cough) as the Queen making salad dressing ("too oily" she opines), Prince Philip grilling sausages and even Her Majesty buying her youngest son an ice cream.
The rationale was it would be a PR boon for a family during the social upheaval of the decade.
Instead, the outing was viewed as a dramatic miscalculation, dashing the mystique of royalty and failing to make them seem relatable. As essayist Walter Bagehot wrote during the reign of Queen Victoria, "We must not let in daylight upon magic."
(Such was the gravity of the situation the actual film has been locked away in the Windsor Castle archives and only very brief snippets are still available. It has not been seen in its entirety since the early 70s.)
That lesson, about just how much access to grant the prying public about what goes on behind palace gates is one that the Queen has assiduously heeded since then. Too much normalcy, too much frying sausages together and clattering about with Tupperware, dangerously dulls the stardust magic of monarchy.
That particular threat, of letting far too much glaring, harsh light in on the goings on of the Windsors, is looming once again, with the royal family facing the release of a hotly anticipated biography about Harry and Meghan the Duke and Duchess of Sussex called Finding Freedom: Harry and Meghan and the Making of a Modern Royal Family.
Earlier this year it was revealed that Finding Freedom's authors, royal journalists Omid Scobie and Carolyn Durand, had been working on a biography about the Sussexes since 2018.
Not only that, they had interviewed 100 people connected to the couple and that Harry and Meghan themselves have co-operated with Scobie and Durand.
(In May, a spokesman for the Sussexes denied they had given interviews and said "there has been no organising from our side in terms of who they have spoken to. It is not an official, authorised or endorsed book." However, per the spokesperson, the Duke and Duchess were "relaxed" about the authors' having spoken to people "close to them.")
For the private secretaries and press secretaries of Clarence House, Kensington Palace, and Buckingham Palace, there must be a certain feeling of deja vu. In 1992, royal journalist Andrew Morton published a biography of Princess Diana that redefined "bombshell" status.
For the first time, there in harrowing black and white, were details about her experience of an eating disorder, suicide attempts and the misery of her crumbling marriage to Prince Charles. (While Diana's involvement was only confirmed after her death, the fact several people from her inner circle went on the record immediately lent the book unprecedented legitimacy.)
Royal biographies might come and go, but already there is already a heady whiff of Diana: Her True Story about Finding Freedom. Though scant details have been released about the book, if nothing else, the title seems to suggest that Harry and Meghan will be cast as having to essentially tunnel their way out of a harrowing existence to find happiness. Already, this hardly bodes well for The Firm.
Similarly, despite the book not hitting shelves for nearly two months, there are already stories cropping up in the British press about it, quoting royal sources and aides, suggesting that a few aristocratic brows are starting to sweat.
In May, a senior palace source dismissed Finding Freedom, telling the Sunday Times: "It was a soap opera. Everyone knows the narrative that's coming. The feeling is that drama and everything that comes with it has left. Let the rest of the royal family get on with it."
(Perhaps "palace sources" doth protest too much …)
Then, earlier this week, The Sun reported that royal aides are concerned that in the book, Prince William will be "painted as the bad guy".
A source told the newspaper: "The concern is it will somehow paint him as an unfeeling baddie against kind and philanthropic Harry and Meghan.
"The aides are privately worried about it.
"Unsympathetic, unfeeling and unsupportive are the words being used but of course no one knows exactly what's in it."
The same source said that the fear was that "the book could be the most damaging thing to the Royal Family since Prince Diana's interview on Panorama".
That fear might not be wholly unplaced. No matter if Finding Freedom does not cast William as the balding "baddie," the book's release will unquestionably revive the personal drama that has shaken the palace for the last two years.
Complicating matters further is the extent to which Harry may or may not have been involved. Veteran royal biographer Phil Dampier, writing in The Sun, commented: "If Harry is giving his approval for the book it will mean the rift between the brothers is getting worse."
Putting family spats, quarrels and petty rivalries, at the centre of the narrative is exactly what the Queen learned nearly 50 years ago was so dangerous: It rendered the Windsors into simply looking like a family, albeit a wildly wealthy and aristocratic one. Basically, it made them far too human.
Even if Finding Freedom fails to offer up any tantalising insights into Harry and Meghan journey from royal golden couple to palace escapees, the one thing it is likely to do is cast William as an all too normal bloke, one who elsewhere has been alleged to have questioned his brother's choice of bride.
Outings such as Morton's Diana mire the royal family in plebeian family turmoil, stripping them of dignity and majesty. The threat potentially posed by Finding Freedom, is that likewise it will chip away even further at whatever awe and mystique remains around the royal family – and that is a dangerous path for a future king (William) to be on right now.
Nearly 30 years since Morton (aided by Diana) tore back the curtain on royal life and offered an unflinching, damaging view of palace goings on, while Harry and Meghan have found freedom, the Queen & Co now find themselves facing the possibility of history repeating itself.
• Daniela Elser is a royal writer with more than 15 years experience working with a number of Australia's leading media titles.