Frida Kahlo said that when she was 18 she realised ”a battlefield of suffering was in my eyes. From then on, I started looking straight at the lens, unflinching, unsmiling, determined to show I was a good fighter to the end.” One photograph exists that predates this realisation — in it, she was a stocky wee four-year-old with an amazingly bullish expression. If there’s a battle going on in that face, it’s between ice cream and custard.Fourteen years later, and until her death, her face has its resolutely constant expression, which is exactly as she describes it.Kahlo’s features have a kind of strength and symmetry that is at once bold and ambiguous — like Che Guevara’s and Marilyn Monroe’s, her face would be iconic even if she wasn’t (though, clearly, it would be quite difficult to prove that). The monobrow compounds her soldierly mien. In some photos she is straightforwardly, movie-star beautiful; in others she has a Joan of Arc gravity. You can see why she is such an idol of the feminist movement, and it’s not just because she didn’t shave her tash — she has a kind of sexiness that doesn’t mask her intelligence, but rather, is a function of it.How Kahlo managed to convey so many shades of mood, while never brooking the slightest alteration in her features, is a strange, strange business. The world’s second-most famous moustache (after Hitler’s) is the least memorable thing about this face.Until the 1980s revisionism Kahlo’s life — as far as history was concerned — began when she married Diego Rivera in 1929. Her own painting didn’t make it into the surrealist canon until long after her death, even though she was the first woman ever to sell a painting to the Louvre.Rivera said of her: ”Frida is the only example in the history of art of an artist who tore open her chest and heart to reveal the biological truth of her feelings. The only woman who has expressed in her work an art of the feelings, functions, and creative power of woman.”She always, for him, encapsulated feminine qualities of truth and endurance. The broader modern recognition of Kahlo as an artist has occurred partly through a new kind of feminist art criticism (that steers away from giving everything a gynaecological spin), and partly through the vast devotion of collectors such as Madonna, who paid so much for a Kahlo painting that it promoted her immediately, cost-wise at least, to the ranks of Picasso and Van Gogh. (The gap-toothed singer professes to identify with Kahlo’s ”pain and her sadness”. Oh please.)Kahlo’s legacy as a photographic subject has long been reflected by her iconic status (like Patty Hearst, she’s been appearing on T-shirts and arty refridgerator magnets for a couple of decades) — the main reason for its great wealth is that she gathered around her the most groundbreaking photographers of the first half of the 20th century. Imogen Cunningham, Lucienne Bloch (Ernest Bloch’s daughter), Tina Modotti (photographer and communist spy), Edward Weston, Gisele Freund and a great number of others all came to Mexico to hang out with Kahlo and Rivera.They established a kind of Mexican Charleston (the Bloomsbury-set house in England, near Brighton), fermenting with creative activity, drinking a lot, having affairs with each other and painting their names on the doors in case they forgot who they were meant to be sleeping with. Only the house was painted purple, it was in Mexico and Maynard Keynes never stayed there, so it was, of course, much cooler than Charleston.Kahlo was born in 1907, although in her teens she shunted this date forward to 1910 (opinion differs as to why — some say that it was so she could stay at school, others that she wanted to identify herself more strongly with the birth of the Mexican revolution. Whichever, it wasn’t to lop three years off her age — she wasn’t that kind of girl). Her father was Guillermo (né Wilhelm) Kahlo, a Hungarian Jewish emigré; her mother a devout Catholic, Matilde. Biographers divine a tension between the two religions throughout Kahlo’s life, though since she spoke little about faith, that’s hard to call — though much could be interpreted from the fact that, every time she’s photographed outside a church, she looks less like a good fighter and more like someone who’s just thieved a devotional candlestick.By the time Kahlo married Rivera when she was 22, the most painfully decisive events of her life had already happened — an attack of polio when she was six left her with a withered leg, and an amazingly gruesome trolley-car accident when she was 18, in which a steel pole entered her body through two vertebrae and exited through her vagina, rendered her plaster-bound for months. Her life as a painter sprang from the grinding tedium of recovery — never formally trained, she started doing self-portraits from her bed. In the many bed-ridden periods of her life (she endured something like 32 operations), she carried on painting in this manner, to which some critics attribute the fact that more than one-third of her work is self-portraiture.In the Hollywood hagiography Frida, starring Salma Hayek and now a hit on the art movie circuit in South Africa, Kahlo springs from her full-body plaster cast lissom and desperately in love with life, delighting in booze and landscapes and suchlike. This wasn’t exactly as it happened — her nature was melancholic with bursts of raucousness, she made several attempts at suicide and was in pretty much constant pain. The tequila (and) sunrises weren’t the half of it.Her father called Kahlo and Rivera ”the dove and the elephant” when they married, which makes a kind of sense, given her slenderness and his comically giant tummy. Looking at the pair of them together, though, he never dwarfed her in any sense other than bulk. She looks hawkish and penetrating; he looks bearlike, sex-dazed and — defying the cliché of artist and muse — a bit needy.There was a strong sense of carnival and fancy dress in Kahlo and Rivera’s relationship. He liked her to wear traditional Mexican garb and she, given her fierce sense of national identity, took this seriously, spending ages twisting her hair into indigenous styles and making people watch (well, they liked to watch).But there’s some subversion going on, since the more extravagantly feminine her outfit, the more of a faintly sardonic warrior there is in her face.The pair were always having affairs, he with most of the people he met (including Frida’s sister, which rankled), she with most of the people who came to stay with them, which, since she did men and women, added up to an equivalent pool. There’s no suggestion that she had a great love other than Rivera (when they did split up briefly, they remarried within a year), but you could do a pretty efficient study of mid-century communism in the Americas by looking no further than her little black book.Famously, she had an affair with Leon Trotsky, after Rivera had petitioned the Mexican government to give the airbrushed thinker and his spouse refuge when Stalin was after them. When Trotsky was done over with the ice-pick, Kahlo was actually taken in for questioning by the police, before some bright spark realised that it must be Russian work. Kahlo and Rivera apparently joked afterwards that they’d entrapped Trotsky in Mexico as a favour to Stalin, but this hard-boiled gag could have been some kind of making-up gesture on her part.Among the many posthumous critical decisions made about Kahlo and Rivera, one of the daftest is that their late allegiance to Stalin turned them into ”bad artists”, and — unlike Ezra Pound with his anti-Semitism — they never atoned properly for their political mistakes. (This view is most winningly propounded by Nobel prize-winner Octavio Paz, but it is effectively nonsense. It wasn’t so long ago, after all, that people were wondering whether it was possible to be an artist without being a communist.)Most irritating in the study of Kahlo alone is the critical consensus that her paintings can mainly be interpreted as a longing for children she couldn’t have (she had a number of miscarriages). In fact, she was deeply ambivalent about children; her letters betray no desire for them at all and, whenever she was pregnant and prescribed bed-rest, she chose instead to do something strenuous, such as learning to drive (well, it’s not strenuous any more, but it was in those days, with their rubbish cars). But she often paints herself with a pet monkey, which is taken as a symbol of broodiness (in fact, symbol-wise, she tended towards the bloody and coarse — chopped off hands, internal organs emerging unbidden from orifices and plopping to the floor).Judging from the photographs, she did have a lifelong fondness for young pets — besides the monkeys, she had a brace of small dogs with no hair, a number of birds and, in one memorable portrait by Bernard Silberstein, a baby goat. Again, like the flamboyantly female clothes, there is a distinct hint of ironic distance in these putatively maternal poses.Kahlo died at the age of 47; it may or may not have been suicide. She had been plunged into a gloom some time earlier by an attack of gangrene and the subsequent amputation of her leg. If her relentless feats of physical endurance are legible from her own paintings, they are nowhere visible in these photographs. It must be some kind of optical illusion cast by the unflinching, unsmiling eyes, but she has a hero’s stature and a disarming physical presence. Even in death, her face is full of thought and challenge. — Â