here’s something about the feeling of finally standing in front of a painting that you have only known through the pages of books. It is not just the psychological shifting of dimensions (they are usually bigger, or smaller, than you imagined), but a sort of stirring recognition: “There you are.” The surge of emotion I felt standing in front of Susannah and the Elders – painted by a 17-year-old Artemisia Gentileschi in the same year she was raped by the artist who was hired by her father Orazio to teach her – was as powerful as any I have felt in my life. In it, a nude Susannah twists away from the two old letches with horror and disgust; unlike many of the nudes painted by male artists, her body is not an exercise in containment, static and mannered as though it could have been carved from marble: it is living, moving flesh. Why this painting? Why now, as the first exhibition dedicated to the work of Artemisia opens at the National Gallery? I haven’t visited a museum or art gallery in months, so there is that. But also: I have spent years thinking about this painting and this artist. She means something to me, as she does to the many feminist art historians who have dedicated their research to her, and the many, many other women who have admired and empathised with her art. And empathy is of course key: many women will look at Susannah and think, “been there”. Artemisia was a survivor of male violence, just as I am. Tears sprang to my eyes when I looked at the transcript of her torture during her rapist’s trial, and read that she had repeated “è vero, è vero, è vero” (“it is true, it is true, it is true”). In her later version of Judith Beheading Holofernes, the man’s hair pokes through between her tightened knuckles as she holds him down while cutting off his head. This has been called a revenge fantasy, and it is one Gentileschi returns to. At the National Gallery, we also see the aftermath: the head in a basket, Judith and her maidservant turning as though they have heard a noise, complicit in their crime. The rape is important because without this vital piece of context our understanding of this great artist will always be limited. A large part of why Gentileschi captivates is because she triumphed against patriarchy. Despite the many barriers that existed for women artists in her time – the 17th century – she was hugely famous. There is also her reclamation by feminist art historians after years of dismissal by the male art establishment (she can only be called an undiscovered genius if you are deliberately ignoring many decades of feminist writing and scholarship). But this battle is not her whole story. It is so easy to foreground the rape revenge fantasy, the blood and the gore and the drama of murder. To focus on that at the expense of all else does her disservice. As Griselda Pollock has written, Artemisia’s fame is “more a matter of notoriety and sensationalism than of any real interest in or comprehension of ‘Gentileschi’ as a set of artistically created meanings”. Focusing mainly on the revenge stuff is a bit like saying you’re a Kate Bush fan but only ever playing Hounds of Love. I hope the National Gallery show changes that: curator Letizia Treves has certainly made the case for Gentileschi to be seen in the round, as the supremely gifted artist she was. The moments of the show that moved me most were the details: the creases of flesh at Susannah’s armpit and at her waist; the way Zeus, in the form of a deceptively delicate shower of gold coins, makes his way into the crease between Danaë’s thighs; Cleopatra’s bluing lips. Artemisia’s features, in the guise of myriad saints and figures from myth and religion, are everywhere. As Laura Cumming wrote, she “seems to live inside every role she depicts”. I delighted in this, but other visitors did not. “Self-obsessed”, said one older man, and I laughed to myself because, really, his remark was just too perfect, too predictable, too tediously sexist for words. The history of women and art has been, in the main part, a history of bodies. Bodies stripped of clothing and imagined and objectified by men. Yet running alongside this parade of breasts and bottoms as conceived by the male gaze is a subversive counterhistory: that of women artists seeing themselves. Some think that a 17-year-old Gentileschi modelled the nude figure in Susannah and the Elders on her own body – an idea that is radical and daring. The first female nude self-portrait in western art history is generally thought to be by the modernist painter Paula Modersohn-Becker. That was in 1906. Gentileschi painted Susannah in 1610. It is not a self-portrait by conventional standards, but we can trace a line from there through to the work of many women artists concerned with what it means to live inside their bodies, from Frida Kahlo to Ana Mendieta, Cindy Sherman to Zanele Muholi. It is Artemisia’s place within this sweep of history that left me staggered. In Seeing Ourselves: Women’s Self-Portraits, the art historian Frances Borzello makes the argument that female self-portraiture should be considered a distinct genre. I agree. In Artemisia’s Self Portrait as the Allegory of Painting, Artemisia is not a victim, or an avenger, or a naked object, but a serious artist engrossed in her work. She was a genius. Take your daughters. • Rhiannon Lucy Cosslett is a Guardian columnist