For decades, courtiers, Downing Street and Whitehall have been beavering away on Operation London Bridge, the extraordinarily meticulous and detailed plan that swung into effect in the early hours of Friday morning (AEDT), with the death of Her Majesty The Queen.
From the pall bearers who will already be practising carrying a lead-lined coffin to the three trumpeters who will appear on a balcony of St James's Palace on Saturday (UK time), before the garter king of arms reads the new king's proclamation, there is not a single detail that has not been plotted and set down in triplicate.
However at some stage in the coming weeks and months, as the UK and the world slowly acclimatise to the accession of King Charles III and Queen Camilla, there is one very awkward situation that will inevitably rear its head: Her Majesty's will.
Earlier this year, the Sunday Times' Rich List put the nonagenarian's fortune at about $630 million, that is how much she was personally worth rather than the billions of dollars of investments, property, jewellery and art that is owned by the Crown, having made about $8.5m in her final year via the booming stock market.
No matter the best estimates, the exact extent of the Queen's wealth, and the robustness of the House of Windsor's coffers as a whole, have always been largely shrouded in opacity and secrecy.
So how many of her hundreds of millions of pounds might go to her son King Charles III and her other three children – Princess Anne, Prince Andrew and Prince Edward? We will never know, thanks to a one-of-a-kind legal loophole that only applies to the royal family and which only six weeks ago was being fought over in court.
By law, every single will in Britain is publicly available but for more than a century, the monarch and their family have been the recipients of a unique legal practice that means they can apply to be exempted from this legal requirement.
Never once has a judge denied a royal application for secrecy.
Today, Sir Andrew McFarlane, president of the Family Division of the High Court, is the custodian of a safe that contains the last wills and testaments of 33 members of the extended Windsor family. (Diana, Princess of Wales was a notable exception.)
In the near future, it is highly likely a 34th will, will be added to that safe.
To understand how this highly unusual legal situation came to pass, you have to rewind to 1910 when Queen Mary's brother, the notorious gambler and womaniser Prince Francis of Teck, suddenly passed away at the age of 39. (He had caught pneumonia while staying at Balmoral.)
It turned out that he had left some highly valuable jewellery, known as the Cambridge emeralds, to his mistress the Countess of Kilmorey.
Mary, who at the time was the Duchess of York, was terrified that news of the bequest would set off a serious public scandal and so she persuaded a judge to seal Francis' will.
(In 1911, when she was crowned queen with husband King George V, what did Mary choose to wear? None other than those Cambridge stones.)
Today, Prince Francis's will is just one of the dozens that Sir Andrew has under lock and key.
In the last year, this controversial tradition has become the subject of renewed debate and even legal action in the UK.
In April 2021, Queen's husband of 73 years, Prince Philip, the Duke of Edinburgh passed away, with the Sun reporting the following month that the Duke had left behind a $51 million fortune, a staggering sum given his parents were penniless and he never held a paying job. (The same report said that, touchingly, he had included bequests to his private secretary Brigadier Archie Miller Bakewell, his page William Henderson and valet Stephen Niedojadlo.)
Last September, Sir Andrew agreed to the royal family's confidential application for the Duke's will to be sealed, with the hearing being held entirely behind closed doors and the media excluded from proceedings.
Since then, the Guardian has waged a legal battle over the secretive process with Caoilfhionn Gallagher QC, acting for the paper, telling the court in London in July this year that "an entirely private hearing such as this is the most serious interference with open justice".
Despite the challenge, the same month, three appeal court judges ruled that Sir Andrew had been correct in barring the press from the hush-hush hearing.
That means it will be the year 2111 before there is any chance that the world might possibly learn how much money Philip left behind and where it went, and only if the future monarch's private solicitor, the keeper of the Royal Archives, the attorney-general and any surviving representatives of Philip decide it should be made public.
This might now be settled law but in the court of public opinion, these special provisions afforded the royal family are highly contentious, with accusations that they are used to obscure the family's financial dealings.
For example, like Philip, when the Queen Mother died, she left behind a mysterious fortune, reported to be about $119 million, and which included a trove of jewellery that had been given to her while she herself was the Queen in the 1940s. That valuable haul went to her daughter the Queen and, if she had been anyone else, such a legacy would have attracted a hefty inheritance tax bill.
(In 1993, when Her Majesty was hashing out a deal with Prime Minister John Major in regards to paying incoming tax for the first time, they also came to an arrangement that bequests from the sovereign would not be taxed.)
While this was all entirely legal, such fancy footwork has only added to the impression of a less-than-forthright Palace unwilling to shed even a smidgen of light on their wealth.
So, will the Queen's death and her will reinvigorate the debate over whether members of the royal family should be afforded special treatment? Will, in a time of increasing calls for transparency, such covert manoeuvring still fly? And might the royal family face a new courtroom fight on this front?
On Friday morning (AEDT,) Charles acceded to the throne and some members of Her Majesty's family inherited millions. We just may never know who became a whole lot richer today.