They say that revenge is a dish best served cold. If it can be broadcast to a global audience of millions, then the garnish is that much sweeter.

There have been many high-profile television interviews before, and those involving the Royal Family have always had a particular kind of prurient fascination. One thinks of Princess Diana’s revelatory Panorama session from 1995, which was watched by 23 million people and saw her reveal that “there were three of us in this marriage”. Or, more recently, Emily Maitlis’s expert dissection of Prince Andrew, in which, seeking to draw a line under rumours of corrupt behaviour, the prince managed to make the situation a hundred times worse, not least with his allusions to being unable to sweat due to having been shot at during the Falklands and, of course, his unlikely visit to Pizza Express in Woking.

The Sussexes are seen as disappointments in Britain and inspirational in America

Yet these have been dwarfed by the deafening, roaring hype that has accompanied Oprah Winfrey’s interview of the Duke and Duchess of Sussex. It has been expertly teased for weeks, with every statement from Brand Sussex carefully calibrated to build interest. And the brief clips that have emerged from the programme, including Oprah saying, “You’ve said some pretty shocking things here”, have led to front page news stories for days, many of which have speculated breathlessly that some existential damage will be done to the Royal Family. It is not for nothing that British papers have been full of stories of both Harry and Meghan having allegedly bullied staff, as the courtiers get in their pre-emptive revenge before the show is aired.

By now, most people have a fairly clear idea of what they make of the Sussexes. Broadly speaking, they are seen as disappointments in Britain, and inspirational in America, but there are endless nuances and distinctions along the way, many of which revolve around age, education, race, gender and attitudes towards the Royal Family in general. But the Oprah interview has been breathlessly billed as the (formerly) royal couple’s chance to set the record straight, with a sympathetic but by no means sycophantic interlocutor, and to make public their plans for their American future. As Meghan says, “It’s really liberating to have the right – the privilege, in some ways – to say ‘Yes, I’m ready to talk’, to be able to make a choice on your own, and to be able to speak for yourself.”

But does the programme remotely live up to the weight of expectation? Somewhat surprisingly, it does, and then some. As Valentine Low wrote in The Times, “Whatever the royal family was expecting from the interview, this was worse.” Over the course of two excoriating hours, largely but not entirely led by Meghan, The Firm, as it has been nicknamed, found itself accused of racism, snobbery, emotional retardation and being utterly unequipped for the twenty-first century on an existential level. Although Buckingham Palace’s greatest fear, that the Queen herself would be traduced, did not come to pass, there were more than enough ad hominem attacks on others – named and anonymous – to satisfy the most prurient of gossips, all expertly presented in a fashion “more in sorrow than in anger”.

The pair repeatedly chose to use the terminology of confinement and escape to describe their situation

The central accusations presented by Meghan were that she, by dint of her skin colour and heritage, was always regarded and treated as an outsider, and that her husband, still deeply affected by the loss of his mother as a child, had never been given the emotional support that he needed from an institution that still preferred the unofficial motto “Never complain, never explain”. Over and over again, in emotive language, the pair chose to use the terminology of confinement and escape to describe their predicament, with Meghan saying that she felt trapped and utterly let down by those that she had (reluctantly) trusted. As she put it, devastatingly, “My regret is believing them when they said I would be protected.”

While Meghan, especially, has suffered from a bad press in Britain, with widespread public scepticism as to the veracity and integrity of her many claims of ill-treatment, this interview has been intended to act as the definitive counterpoint to high-profile sceptics. Perhaps the centrepiece of the encounter came when Meghan confessed to having felt suicidal due to the bad treatment that she received, saying, “I just didn’t want to be alive anymore. And that was a very clear and real and frightening constant thought.”

Yet some claims made during the interview may have been exaggerated for emotive effect. It seems deeply unlikely that, when she confessed her fears to an unnamed member of staff at the Palace, that they coldly responded, “My heart goes out to you because I see how bad it is, but there’s nothing we can do to protect you because you’re not a paid employee of the institution.” And if it was not Prince Philip who said, alluding to the skin colour of “the first royal baby of colour”, “What will the kids look like?”, then there will now be a press witch-hunt to discover which other member of the royal family has apparently racist and unreconstructed views.

Those with long memories and some understanding of royal history will draw parallels with the situation that arose eight decades before between Edward VIII, Wallis Simpson and the reluctant George VI. Both Edward and his brother had a stern, dictatorial father in the shape of George V, and Prince Charles emerged badly from the Oprah interview, with Harry saying that he had refused to take his calls and that he had cut him off financially as a result of their decision to step back from the royal family.

The reputational boost to Brand Sussex from this interview will be incalculable

Just as money, and the perceived lack of it, played a central role in the fatal estrangement between George VI and the Duke of Windsor, so it seems equally clear that Harry and Meghan have been concerned about their own financial situation; while it was made clear that they have not been paid to participate in the interview, the reputational boost to Brand Sussex will be incalculable. And it was a major bone of contention between Edward and George that Wallis was never granted the HRH status that she craved, just as Meghan and Harry’s first public allusions to feuds with William and Kate – how easily one falls into first name familiarity with these people, like characters from a soap opera – will lead to days, perhaps even weeks, of tabloid headlines and speculation.

The Queen herself, who remains a popular figure in America, may have been praised by Meghan as “wonderful”, with Harry taking care to call her “my commander-in-chief”, but otherwise the revelations represent a hammer blow to the institution of the royal family that may, in its own way, be even more devastating than the events of the abdication and Princess Diana’s televised revelations. Both of those essentially revolved around the peccadilloes of human behaviour in bizarre and heightened circumstances, and could be put down to a form of grim experience.

But this was different. If Buckingham Palace does not find an effective and definitive way to counter the accusations – and the image of a young, pregnant, mixed-race woman crying on television as she recounts the appalling treatment that she faced at the hands of a hidebound institution is a deeply affecting one, whatever one makes of her claims – then questions that have not been asked for decades, if ever, about whether the country needs a royal family after the end of the current reign are likely to surface once again. This Oprah interview may yet be seen as one of the most significant turning points in our country’s chequered, complex relationship with its monarchy.