In the end, months of conspiracy theories were silenced by a two-minute video.

After a strict media embargo, on Friday at 6pm, Kensington Palace released the statement recorded personally by Catherine, Princess of Wales.

In it, she revealed that, following her abdominal surgery in January, doctors had discovered cancer, and she was now being treated with preventative chemotherapy. She explained how she had sought to share this news appropriately with her young children, reassured the public that she was growing stronger, and finished with a moving message of hope to others undergoing treatment for the disease.

It would once have been unthinkable for members of the Royal Family to share details of their medical conditions, and yet, this seemed like the least extraordinary aspect of the video.

The closest comparison is perhaps 1997, following the death of Diana, Princess of Wales, when public and media disquiet effectively forced the Queen to address the nation.

Commentators have been divided on whether Kensington Palace was similarly forced into the statement as a result of mounting public pressure or if Kate would always have explained the details of her condition and was choosing a moment (the beginning of her children’s Easter holidays) that suited her.

Either way, the intense public and media pressure was undeniable. That tells its own story.

In 1997, the ‘public’ could only make its views known through opinion polls, mass gatherings, direct interventions (such as vox pops or letters) and, ultimately, through its arbiters in the press. Social media has upended that framework.

Newspapers now follow the internet’s lead. For weeks, conspiracy theories around Kate's absence from public life dominated the conversation on Facebook and X (formerly Twitter), and ranged from light-hearted nonsense to poisonous defamation.

In two clear ways, that leaked into the mainstream ecosystem.

The first surrounded the Mother’s Day photograph on 10 March, presumably released by Kensington Palace to reassure people that Kate was happy and well, surrounded by her family. UK media outlets published the image as issued and only began discussing the edits made to it after analyses began to trend on social media.

That was followed by ‘kill notices’ issued by multiple international press agencies, effectively declaring the photograph unfit to be used – a damaging rebuke to Kensington Palace and its credibility. That, in turn, led to a highly unusual tweet signed by Kate herself, in which she apologised and claimed responsibility for editing the picture as an "amateur photographer".

The second involved another type of photography: an amateur video at a Windsor farm store, purportedly showing Prince William and Kate in good spirits carrying shopping. Crucially, this video was published by the Sun – providing a key contrast with an earlier paparazzo photograph of Kate and her mother Carole Middleton in a car, which was only published abroad.

Some commentators questioned whether Kensington Palace had tacitly approved the video’s publication. Even more significantly, however, some mainstream journalists – notably Rachel Johnson in the Evening Standard – questioned or openly doubted whether the woman was really Kate at all. This might, once again, have demonstrated an example of social media conspiracy spilling into the mainstream – or, more troubling for Kensington Palace, a new dent in the armour of deference which still pertains to William and Kate in a manner that long ago escaped Prince Harry and Meghan Markle.

This notion of deference is important.

In some ways things, have not significantly changed since 1936 when American newspapers openly discussed King Edward’s relationship with Wallis Simpson and the British media remained entirely silent.

Foreign media has aired theories about Kate that would not have been touched here. There still exists in Britain a culture either of widely-known open secrets or of journalists hoarding information about the Royal Family – and either dropping small public breadcrumbs or remaining entirely silent.

In some ways, that is legitimate: members of the Royal Family are human beings with the right to a private life. But they are also public figures with, crucially, public and constitutional roles.

This feeds into the most fundamental tension in our modern monarchy: the codependence of members of the Royal Family and the royal press pack.

William and Kate are considered positive assets by both the tabloid media and the monarchy itself – the press’ treatment of them is a far cry from the hounding of both William’s parents in the 1990s. That is a product of multiple factors: a change in tabloid and paparazzi culture, the fact William and Kate have not yet been publicly linked to a tabloid-friendly scandal, and because the couple cooperates.

The media knows that the Royal Family sells newspapers and seeks access. The Royal Family knows that the media sustains both public support for the monarchy and people’s appetite for information about it, and seeks positive coverage. Underlying both anxious institutions is the British public, on whose patronage both depend.

Ordinary people were concerned about Kate’s welfare, but they also wanted information as they would about any other high-profile celebrity. Kate, in turn, was entitled to privacy as an ordinary human being, but will also one day be Queen. Such is the woozy confluence of soap opera and constitution. These people function both as fodder for national entertainment and as instruments of the state.

During the past three months, the media has performed a strange dance, balancing a mostly justifiable interest in a public figure with a mostly unjustifiable interest in a private one – sometimes, it appears, with the cooperation of Kensington Palace, and sometimes, it appears, without.

The media wanted to push, but not too hard. The Palace attempted to manage the coverage and, in the end, through Kate’s video, resolved to produce its own. This appears to have been a power struggle that ended in stalemate.

Once this story dies down, the most important soul-searching will probably take place not in Fleet Street but Kensington Palace. Insofar as the monarchy is a political institution, it relies on trust, both from the media and public. Credibility is not easily replaced and the photograph incident will have damaged faith in its communications machine. Now Kate has revealed her diagnosis, more questions arise about why the princess was thrown into the centre of a PR storm while receiving treatment for cancer.

And yet perhaps the greatest question centres on Kate herself.

The monarchy is a barer institution than a few years ago, and a weaker one. While the King and Queen are liked and respected, they do not attract either the deference of the late Elizabeth II or the rock-star appeal of the Duke and Duchess of Sussex. Only William and Kate come close to embodying both the stability and glamour that the institution needs – and Kate above all. She is the most popular member of the family, and so indispensable that the modern monarchy can scarcely be imagined without her.

That, in turn, reflects the vulnerability of the institution: it can only ever be as strong as its cast. It cannot, constitutionally, just disappear – but it can fade into irrelevance or embarrassment. Its sustainability, in current form, can no longer be guaranteed.