The six wives of Henry VIII occupy a curious place in the public mind. We all know who they are; but how many of us know who they were? Unlike most of their contemporaries, it’s not oblivion they need rescuing from, it’s caricature. A new exhibition about them at London’s National Portrait Gallery is pointedly titled Six Lives. It promises to reintroduce us to six distinct and individual women, each compelling in their own right, not just merely tragic adjuncts to the great Henrician psychodrama.

Is official Tudor portraiture a reliable medium for such a message? Formal portraits expressed ideas about queenship, about power and familial status, about fidelity and faith, before they interested themselves in individuality and character. Personality must then be reconstructed out of things like patronage and possessions, and the thin traces of the self that might be left in letters, or the margins of books.

The narrative frame of ‘the six wives’ is a powerful one, but it also imposes a kind of equality on these six women that isn’t necessarily matched in the historical record. As many historians have discovered, to apportion these women equal attention is already to distort their lives. The exhibition thus embodies a historiographical problem. Each individual queen gets a room of her own of roughly similar size, but Katherine of Aragon was queen for over 20 years, with all the political and emotional complexities such a span entails. Neither Jane Seymour, Anne of Cleves or Katherine Howard made 20 months. It is ironic, then, that one of the most powerful objects here belongs to the latter, arguably the hardest of the six to identify and characterise in the archives. It is a letter from her to Thomas Culpeper, a courtier, from the autumn of 1541. Their relationship would be the death of both of them; she was executed in February 1542. She signed the letter ‘yours as long as life endures’. She was probably 18 years old.

It was striking how hemmed in by portraits of men some of these rooms feel. Katherine of Aragon, for example, is flanked on one side by her first husband, Arthur, then a young Henry VIII, Pope Clement VII and Cardinal Wolsey. This is a neat encapsulation of the constant social, political and moral pressure under which these women lived; but it does take up valuable wall-space. The exhibition seems torn between telling these women’s stories, and thus showing us key actors in their lives, and exploring their hinterlands. Perhaps, too, that tension reflects a push-and-pull between portraiture – the gallery’s raison d’être after all – and the choice of other possible artefacts.

A nuanced sense of individual identity is certainly evident. Katherine of Aragon was far from the reactionary Catholic of Protestant myth, and her engagement with the latest humanist thought is revealed here in copies of works dedicated to her by Erasmus and Vives. Anne of Cleves’ account book shows her signing off every page. Two exquisite jewels only – not quite contemporary – stand in for the hundreds we know them to have owned. Both are tantalisingly similar to those in some of the portraits. The current exhibition at Tate Britain devoted to the work of John Singer Sargent marries items of fashion to his paintings; here the passage of time and the intensity of these lives makes the frisson of such connections sharper still.

Misidentification has stalked the portrait history of all the queens, indicative of both the conventional nature of court portraiture and the long indifference of history to the particulars of their lives. One particular highlight, then, is a newly identified portrait of Katherine Parr, formerly thought to be a Holbein portrait of Mary I and now attributed to Master John. The fur, fabric and jewellery are all exquisitely reproduced – it is the specifics of the jewellery that led to the new identification – but it is the face you look at in the end: weary, wary and resolute.

I had the good fortune to see this when it was auctioned at Sotheby’s last year, where it sold for nearly £3.5m; here it is thrillingly united with a portrait of Mary that is, I think, the only other painting now attributed to the artist. Almost nothing, aside from these commissions, is known about him; it isn’t only the queens here whom anonymity stalks. The gallery’s stunning full-length portrait of Katherine Parr closes the exhibition; formerly thought to be Master John’s, it is newly de-attributed here. I doubt you’ll see these three paintings together again.

Another highlight is a pre-marital portrait of Anne of Cleves by Bartholomaeus Bruyn the Elder, which the English complained about so much – they couldn’t see her beneath her ‘monstrous habit and apparel’, apparently – that Holbein was dispatched to do a better job. Her delicate leather gloves lie on the ledge in front of her; she holds a small posy of carnations and gazes, with wistful resignation, into an ill-defined future somewhere off at a tangent to the viewer. It’s simply lovely.

The exhibition has set itself an ambitious task, and in some ways its very structure makes that task harder. It opens with a portrait of Henry VIII. Oh God not him, you think. Henry makes other appearances throughout; it is as if he hasn’t quite got the message that this isn’t about him. Then you are presented with monochrome photographs representing the six wives by the contemporary Japanese artist Hiroshi Sugimoto. These, one is told, explore ‘the tension between the real and imagined’. But what is real about them? They are images of waxworks taken from a larger series of works, which includes studies of models of everyone from Yasser Arafat to Voltaire. In that context, they speak to ideas of fame and explore the point at which identity drains away and the subject becomes all image, all surface. These six models were created at Madame Tussauds in the 1980s, some of which are evidently based on portraits elsewhere in the exhibition. In this context, the images seem no more than portraiture as hearsay.

Three further rooms look at representations of the six women since their deaths. The 17th and 18th centuries were little interested in them: one set of engravings managed to get three of its identifications wrong. It isn’t until the 19th century that you begin to get works like David Wilkie Winfield’s ‘The Arrest of Anne Boleyn’, which fits its subject into the more or less tragic, more or less Romantic mould of Friedrich Schiller’s Maria Stuart or Paul Delaroche’s ‘The Execution of Lady Jane Grey’. This is not to say that there aren’t good things in these rooms. Paul Scheurich’s artwork for Ernst Lubitsch’s 1920 film Anna Boleyn has a surprisingly dark, unsettling presence, for instance. But because these various works and objects either fit the six women to narrative clichés or objectify them through costume the exhibition here seems to enact the process of obscuring that it otherwise aims to reverse.

Nevertheless, no visitor to Six Lives will go away without their understanding of these six women powerfully enhanced. There are some rare and extraordinary things to see, and here and there you start with wonder and experience that eerie, fleeting sensation of a long dead presence somewhere close by, scribbling out a note, turning the pages of a book, or sitting impatiently for an artist, humanly uncertain of what their future might hold.

Six Lives: The Stories of Henry VIII’s Queens is at the National Portrait Gallery until 8 September 2024.