Self Portrait as Saint Catherine, a face from the mirror

You are Artemisia Gentileschi, born in Rome in 1593, the eldest child of the painter Orazio Gentileschi. You learn to paint in his workshop. Among the shortcuts you learn there: keep a cartoon or a tracing of a figure and use it again on another canvas.

At about seventeen you sign and date a large Susanna and the Elders. In 1612 the painter Agostino Tassi, your father's collaborator, is tried in Rome for raping you and is convicted; during the trial you are made to confirm your testimony under judicial torture, with cords tightened round your fingers.

On 29 November 1612 you marry Pierantonio Stiattesi, a Florentine, in Rome. Within weeks the couple moves to Florence.

You set up a studio almost at once in the house of your father-in-law, the tailor Vincenzo Stiattesi, on the via del Campaccio near San Lorenzo; after his death in 1615 you move to Borgo Ognissanti. In Florence you learn to read and write, and you make friends who matter: the poet Michelangelo Buonarroti the Younger, great-nephew of the sculptor, who stands guarantor for you and commissions a ceiling painting for his house; the painter Cristofano Allori, godfather to your son Cristofano, born in November 1615. Through the Academy you come to know Galileo.

On 19 July 1616 you are enrolled in the Accademia delle Arti del Disegno, one of the first women in its fifty years. You look for Medici patronage, perhaps through the dowager Grand Duchess Christina of Lorraine, and paint a Judith beheading Holofernes for Grand Duke Cosimo II.

Who paid for this painting, or whether you made it to sell, is not known. Its origins, and those of many of your Florentine works, are lost.

In your first Florentine years you paint yourself again and again, sometimes as yourself and sometimes in a part: a martyr with a palm, a musician with a lute, a warrior in a helmet, now lost. A mirror is cheaper than a model; years later you will complain of the “intolerable expense” of models. And a woman painter's face is something collectors want.

Head turned

Body to the left, head back over your shoulder to meet the viewer's eye: the same pose as in your lute player.

Close crop

Half-length, the elbow and the wheel pushed out at the picture's edges, so the viewer stands very close.

A cloth on your head

A turban wound round your hair, its fringed end trailing behind you. It recurs in your self-portraits of these years.

A quieter face

Compared with the lute player, the bump on your nose is smoothed and the face less full: you, but idealised, as befits a saint.

The lute player's head.

This painting's head. Tracings of the two align, the National Gallery found.

The imaging shows that the picture began as something else. Under the wheel is a shape, “perhaps a prophetic tablet or, more probably, a book”, which you then covered with a dark paint containing umber. Some of the turban's cloth first fell across your chest, held under your right hand. The headcloth, the book and the pose suggest a learned woman, perhaps a sibyl, the prophetesses of antiquity; or the book was Catherine's from the start, for her learning.

Then you change course. You paint a broken wheel studded with iron spikes over the covered book and part of the background, the instrument of Catherine's torture, and bring the yellow shawl over its edge. Last come the signs of a saint: a gold crown with eight pearl-tipped points, sitting a little awkwardly on the turban; a halo; and the palm of martyrdom, pinched between your thumb and forefinger like a brush, painted over the drapery and the background.

Catherine of Alexandria was a learned princess who, in the legend, out-argued fifty philosophers, refused the emperor, survived the spiked wheels and was beheaded. Whether a client asked for a saint, or you made the change to sell the picture more easily, is not recorded.

Imagined: before the change. AI-generated

After: Saint Catherine.

The Uffizi has another of your Saint Catherines: the same pose, the left arm out on a wheel and the right hand holding a palm to the breast, a red dress and a yellow shawl; but a different woman's face, raised to heaven, under a jewelled crown. Some think she is Caterina de' Medici, the Grand Duke's sister.

When the Opificio delle Pietre Dure in Florence X-rayed it in 2019, a figure appeared underneath: a woman in a turban, looking out, almost identical to this one. Traced from the X-ray and laid over the London picture, its head and turban match almost exactly, and so do the arms and drapery once the tracing is moved a few centimetres. A third, smaller woman's head is in the X-ray as well.

So you traced this figure, or its design, onto a second canvas and painted it well on before turning it into a different saint with a different face. The Hartford, London and Uffizi pictures were made close together, perhaps on your easels at the same time. Your lute player hides a secret too: an X-ray shows a woman's head upside down beneath it, from an earlier picture you turned round and painted over.

Nothing is known of the painting from your studio until the twentieth century, when a French family, the Boudevilles, owned it. It had been lined onto a new canvas, probably in the nineteenth or early twentieth century; its folded right edge had been opened out and its top edge trimmed, cutting the tip of the palm and one point of the crown.

When the National Gallery bought it there was a tear about 4 centimetres long at lower left, a bulge above the crown, losses along the top and the seam, yellowed varnish and old retouching. In 2018 the conservators took off the varnish and the retouching, repaired the tear, relined the canvas and retouched the losses. They added a thin strip of new canvas along the top, just enough to complete the palm and the pearls of the crown; the halo is still cut. Under the old varnish the colours were livelier, but the top red glazes and the yellow lake had faded long before.

As bought, 2018: the photograph published at the purchase.

After the 2018 treatment. Some of the difference is the photography.