OPINION:
The year was 1991 and those closest to Diana the Princess of Wales believed she was at a crossroads: She could either choose "explode or implode", according to her biographer Tina Brown.
By that point, after 10 years marriage to Prince Charles, after suicide attempts, suffering from a long-term eating disorder, post-natal depression and being trapped in an emotionally barren union with a man who was in love with another woman, Diana needed the world to see her desolate reality.
And so, she did the unthinkable and decided to go nuclear. Using her old friend James Colthurst as an intermediary, she lit the fuse when she decided to tell journalist Andrew Morton everything via cassette-taped interviews smuggled out of Kensington Palace. The end result, Diana: Her True Story landed the following year with such a percussive blast it rattled the Queen's fillings.
When the first extracts from Diana: Her True Story were published by the Sunday Times on Sunday June 7, 1992, it set off a shockwave unlike any other that came before or that have hit Buckingham Palace since.
There's a reason for this history lesson, I promise you, because now, exactly 30 years later, Diana's son, Prince Harry, is about to follow in her footsteps and release a memoir, Spare.
While the manuscript remains the most closely guarded publishing secret since Paul wrote the New Testament, the question is, just how devastating could it be for everyone from King Charles down?
In October a source familiar with the book told the Telegraph that it is "not a take-down or tell-all. It's a story about his truth". But one duke's "truth" could end up being another HRH's hell.
With Diana's guerrilla campaign to bring the royal family to heel back in the spotlight thanks to the latest series of The Crown, and with the clock ominously ticking down to Spare's D-Day, the lessons of her publishing offensive have never been more relevant or necessary.
Because while it's totally understandable why Diana did what she did, the case can very much be made that it was a gross miscalculation on her part.
Let me explain.
So, the year is 1992 and Diana's Morton escapade started off with a serious bang, with its Times serialisation leaving not only the UK but the world both shocked and horrified at her pain and misery.
As her friend from Oonagh Shanley-Toffolo reportedly said: "She is a prisoner of the system just as surely as any woman incarcerated in Holloway jail."
If the princess had wanted to exact retribution on the Palace for the decidedly dud deal they had foisted on her in the form of her marriage to Charles (and the expectation she would meekly wither in silence) then boy, did she get it. (Republican sentiment reportedly jumped following Diana's publication).
Her personal victory extended to her mental health, according to Brown, with the princess's bulimia abating - for a while at least - and her sleeping properly for the first time in a decade.
But her joy and hard-won peace did not last long.
A week later in mid-June, Diana sat down with the Prince of Wales and his parents, Queen Elizabeth and Prince Philip, at Windsor Castle for a meeting that left her "shaken rigid", according to Colthurt's diaries.
Not long afterwards, dutifully having trooped along to Ascot, Diana was left in "floods of tears", a guest in the royal box told biographer Robert Lacey.
"The atmosphere was dreadful. Absolutely no one in the family was speaking to Diana. They were blanking her completely," they said.
Basically, she had broken ranks and was never let back in.
It was one thing to be a thorn in the Queen and Charles' sides behind the thick curtains of the Palace or Highgrove House, but another entirely to take that same unruly attitude out into the world and to expose the royal family's dirtiest of secrets. It was the ultimate unforgivable crime.
While the move helped the princess get the separation she had been asking for (Prime Minister John Major would announce it in parliament six months later) it was a short-term win. Whether she understood it or not, there was no coming back from the apostasy of Morton's Diana and what trust the Palace might have had in her reportedly evaporated.
It has to be noted that her participation with Morton on the book was only officially confirmed by him after her death; however she arranged to be photographed visiting one of her old friends and one of Morton's key sources for Diana days after it was published, thus putting her stamp of approval on the book.
Post-book publication, and separated, the princess' new life might have been "free", finally winning the latitude to pioneer the sort of globetrotting celebrity humanitarian paradigm that is now so familiar, but she was also now out in the wilderness. Royal but also not quite.
Sounding at all familiar?
She was, as Brown writes in her legendary The Diana Chronicles, "a semi-detached Princess of Wales".
The moral of the story here is that Diana got what she wanted – for the world to understand and acknowledge her pain and anguish – but her catharsis came at an exceptionally high price.
It is also possible to trace a line from Diana to the prince and princess's divorce four years later, an outcome Diana reportedly did not actually really want. (Diana triggered Charles to agree to participate in Jonathan Dimbelby's sanctioned 1994 biography and the associated TV interview in which he admitted he had strayed, which led Diana to do her self-immolatory Panorama interview the same year after which the Queen put her foot down and made them formally end their marriage).
It's not the "why" here that is up for debate – that both Diana and Harry wanted and want the world to see and acknowledge what they have endured for the sake of the monarchy is completely understandable.
So too is it also completely understandable if the reported $65 million, multi-book deal the Duke of Sussex has struck with his publisher had played a part given he has his own gas bills and Mommy and Me reiki classes to pay for now. (He has also committed to donating $2.27 million to his Sentebale charity and $531,000 to WellChild).
No, the question here is not one of motivation but, has he really thought through the possible irrevocable consequences of breaking ranks with the royal family in this fashion?
God I hope the 38-year-old has spent many long days and weeks contemplating that in writing this book he is letting a genie out of a bottle that can't ever be shoved back in.
Once Spare is released, he will have crossed the Rubicon with his family. What chance could there be of the breach between him and his brother ever being repaired, of things going back to the way they once were, if he breaks the royal omertà? (There are more similarities between the Palace and the Mafia than their infamous code of silence).
Harry is about to commit the same "crime" as his mother and, just to really flog the metaphor here, in her case it came with a life sentence.
The 90s, the decade covered by season five of The Crown, have to go down as some of the worst years ever since the Hanoverians took over the monarchy. Quite how much of the Netflix series is fact, and how much is fiction, is a conversation for another time but if there is one incontrovertible lesson from that time it is that Palace's propensity to, again and again, let an HRH's rage and hurt go ignored only ever leads to one thing: BOOM.
Daniela Elser is a writer and a royal expert with more than 15 years’ experience working with a number of Australia’s leading media titles
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