Judith Tarr is one of the most accomplished, complex, innovative, and consistently brilliant writers I can think of. She has been astonishing and delighting and challenging me since I picked up her first novel The Isle of Glass on its first UK publication in 1986. She writes SF and fantasy, historical fiction, YA, and slipstream, and all of her books are characterised by a crisp, engaging, and beautiful writing style. She is the mistress of detail; her ability to depict believable, realistic cultures in a handful of perfectly chosen words is equal to that of George R. R. Martin. She was "grimdark" before it was invented, she was creating complete histories of grittily imagined worlds (as opposed to the mythic sweep of Tolkien) before it was fashionable. Her depth of knowledge is astonishing.

And yet, it seems, Judith Tarr does not exist. Across her long career, pretty much every single one of the strategies documented by Joanna Russ to suppress women's writing has been wielded against her to keep her on the margins. She is seldom if ever reviewed. Her books are not discussed outside the tight circle of her fans. (And she has a lot of fans. I keep meeting new ones, each of us wondering out loud how it is she remains so ignored.) She is not seen. She is almost the perfect example of the problems facing women in SF to this day: we are condemned from our inception to obscurity unless we are very, very lucky or, perhaps, both very, very, very gifted at self-promotion and strong-minded enough to withstand the hostility that women promoting themselves face. We are told, dismissively, "Oh, well, if you're good enough, people will recognise that," but people do not recognise the books they do not read, and too many people simply do not read books by women. I have had more than one man explain to me why he does not need to read Tarr. He knows what her books are like unread—just romance, really, right? (The answer to that one is no, by the way.) And anyway, he's read historical fantasy (by a man). He doesn't need to read the girly version.

I say "man" in that sentence advisedly, because to date it has always been men who have said that to me, and they have been saying it to me since, well, 1986. I tried to get my university fantasy society to include Tarr on the list of authors we would discuss that term and was told we didn't need to—we would be discussing Guy Gavriel Kay, and that meant Tarr was unnecessary. When it comes to historical fantasy, like English pronouns, the male includes the female, apparently. The same society had already dismissed as unnecessary almost all the other women then writing—including Tanith Lee and Katherine Kurtz. We were allowed Le Guin and Anna Kavan, and, I think, Angela Carter. Apart from that, it was men all the way. (Several of whom, I was told, were probably "too difficult" for me. Women's brains overheat when faced with SF, it seems, at least at the University of Cambridge in the 1980s.)

It's tempting, in retrospect, to wonder why I didn't simply tell those young men that Tarr was probably too hard for them. Tarr is not an easy writer. She makes substantial demands of her readers, and she expects you to keep up with her breadth of knowledge and sophistication of thought (something she shares with another fine woman writer who debuted around then, R. A. MacAvoy). Tarr is a professional historian and literary scholar, and the societies she depicts are deeply rooted in her academic studies. Her characters do not conform to modern standards of behaviour, do not react in the ways our modern psychology expects, and rarely if ever emote. The pasts she depicts—some of them real (twelfth-century Constantinople; Amarna-period Egypt; ninth-century Germany and the papal states), some of them imaginary (in particular her SFnal Avaryan series)—really are a different country. This is challenging stuff.

Tarr frequently takes modern theories of how particular times and places may have been and tests them against rigorously depicted, rigorously researched models of the cultures in which they may have operated. White Mare's Daughter succeeds in giving a depth and conviction to the contentious hypothesis of Marija Gimbutas of an early Palaeolithic matriarchal cult being displaced by incoming patriarchal migrants and makes it both comprehensible and very human. (I still don't believe in the theory, and I suspect Tarr doesn't either, but it's an excellent book.)

Pillar of Fire blends the complex and fragmentary history of the heretic pharaoh Akhenaten with the narrative of Exodus and proposes startling, internally credible answers to some of the most vexed questions about both. In her first sequence, which began with the aforementioned The Isle of Glass, she weaves the real historical narrative of the period from just after the Second Crusade down to the catastrophic Fourth, and of the kingdoms, Christian and Muslim, touched by and involved in both, with a realistic portrayal of the existence of immortals, and of a subtle kind of magic. In terms of historical complexity, this may be one of the most accomplished fictional versions of the Crusades out there: Tarr confronts head-on the fissures and divisions in both the Christian and Islamic worlds, and portrays the real humanity of both sides. There is no good and evil here, only different needs, beliefs, agendas, and opinions. Her protagonists are often wrong, or misguided, or weak. Her antagonists are humane, complex, frequently right. She is unflinching in her depiction of the brutality of war and its cost to everyone involved, and she often relates her narrative through the eyes of those who have the least control over the situation—servants, foot-soldiers, women.

Tarr's writing of women has few peers. She presents women in their full range across her work. We are old and young, married and single, mothers and childless, of all races and faiths and classes. We are powerful and powerless, often both at once along different axes. Perhaps my favourite character in all her work is one of these complicated women, Joanna, in Alamut. Joanna is married, in a political union in which she is a chattel. She is only marginally educated. She has a son, and becomes pregnant again during the course of the novel. She exists in a world of liaisons and friendships that cross boundaries of faith, ethnicity, and mortality. Her story is not consolatory, but nor is it that of a victim. She has agency within her life as her context defines it, and she rises to challenges in authentic and complex ways. She belongs to the world of the Christian kingdom of Jerusalem, and her social circle contains Muslims as well as Christians and Jews, and still she feels like someone I know and understand, even though her psychology is not mine.

This is not the simplified Hollywood world of King Richard and the Crusaders but a historically accurate portrayal of the real twelfth century. If there is such a thing as Hard Fantasy, this is it. (And I could say the same of any other of Tarr's historical fantasies, which range from early Egypt and Crete down into the thirteenth and fourteenth centuries.)  As a writer, Tarr celebrates female agency in all its forms: some of her women are trammelled by the rules of their culture, but others are not, or exist in cultures with different—but historical—rules. Meriamon in Lord of the Two Lands is a doctor, a profession open to women in Pharaonic Egypt, but she is also a part of the army of invasion of Alexander the Great and as such finds herself in a context that does not understand her or her expectations of her rights. She must learn to operate within new constraints—and the men of Alexander's army must learn to understand and respect her—and to respect her faith, which is very different from theirs, for this is a world in which gods are real.

Faith was critical to nearly every early culture for which we have records, and Tarr reflects this. It is far too easy, writing from the twentieth and twenty-first centuries, to downplay, or elide, or simply ignore the degree to which faith was an everyday part of everyone's lives in earlier times. But Tarr resists this tendency, giving us (as with Katherine Kurtz) a credible, comprehensible sense of how faith and religion affected action. Her characters' faith is real; it motivates and informs their every action. Alf, the protagonist of The Isle of Glass, is a monk and struggles to reconcile his deep faith with his discovery of his immortality—which some in his church consider a heretic state. Yet the immortals he meets are as faithful as he, although not all of them are Christians. The religions of the Avaryan series are imaginary, but they nevertheless pervade the societies within the books, and the characters respect their tenets. There is no bending of rules to accommodate the plot, or convenient abandonment of parts of a faith to give a consolatory romantic ending anywhere in Tarr. Alf remains conflicted. In Arrows of the Sun (one of the Avaryan books), the story more or less begins with the end of a central relationship, when the protagonist, Estarion, loses his lover Vanye to her faith, which demands she leave him. She does not come back. She continues to matter to him. But he finds other lovers—notably the young man Korusan. (Tarr's work is not heteronormative, nor gender-essentialist, particularly in the Avaryan series.)

Tarr's body of work—she has been writing for over thirty years and published something like thirty-five books (plus several in collaboration)—is an astonishing achievement. She has probably done more for the field of historical fantasy than any other writer—and at no point does she do what those who dismiss her unread claim, which is file off the serial numbers of real events and put in fantasy names. This is history with its eyes open, complex, realistic, difficult, uncomfortable, powerful, strange. She does not seek to conform to reader expectations of the past, she does not comfort, and she is never, ever sentimental. Her characters are never modern white people in dress-up: they are frequently not white, for one thing. (Like Le Guin, Tarr has written diverse characters with respect and care since the beginning of her career—and like Le Guin, this has often been elided from accounts of her work. Though her covers have tended to be less whitewashed, thankfully.) She is a true master of our genre, and it is long past time that she was recognised and respected for the huge contribution she has made.