THE PAST WEEK has been spent with my nose to the Frida Kahlo trail. I wanted to find out more about her before a show of her work at Tate Modern opens next month. How did the small, sick, moustachioed Mexican who scowls from self-portraits become a cult figure? What turned a teasing, caustic artist with an unbroken eyebrow into an icon?

Several of her old acquaintances still live in Mexico City. And over sticky fruit juices and little sugar-dusted biscuits we would chat. “So what was Frida like then?” That was always the question. But the answers were never the same. She was a flamboyant rebel with a contagious belly-laugh. She was a self-pitying old bat and a bit smelly to boot. The more that I asked, the less sure I got.

But is such elusiveness a testimony to her greatest talent? After a terrible bus crash, doctors had to piece Kahlo together like a papier-mâché model. She reassembled her character in a similar way, creating an image that she could inhabit like a carapace — like one of the plaster corsets that set round her torso and that, bed-bound for months, she would gaily decorate. This is the character that her paintings project. Frida is the only artist who gave birth to herself, a friend once said.

On the bookshelf of her old home, which has been preserved like a shrine, lay a much-thumbed copy of The Picture of Dorian Gray. What resonance this story must have had for Kahlo. Ageing and increasingly drug-addicted, she slowly decayed like the effigy in the attic. But the mask of her paintings became her reality. She merged with her image. She transformed herself, quite literally, into an icon. Which drama queen wouldn’t envy such adroit stage management? Which Heat celebrity wouldn’t die for her publicity control? No wonder Madonna owns two of the Kahlo paintings that go on show at Tate Modern. But there’s no point looking for the truth of the artist who painted them. Her life dissolved into legend long, long ago.

• ONE of Kahlo’s great achievements was to reclaim national pride in ancient Mexican heritage. Her legacy lasts. Travelling through Michoacán, I found the revival of a Pre-Hispanic ball game proudly announced.

  But how do you play Uarhukua? I certainly wouldn’t like to venture a guess. Pre-Columbians, after all, were not known for clean play. The Aztec precursor to Ker-Plunk! involved the decapitation of a player at the end of each round. And that is mild compared with an ancient Mayan version of football in which, as a warm-up, a neighbouring prince was captured and imprisoned in darkness until his skin was bleached. Then, tied up in a bag and kicked about by priests until his bones were all smashed, he was booted to his death down a stony ziggurat. This game, it seems, was designed to score against the devouring gods of emptiness.

  Something (the prince) had to be turned into nothing and fed into the gods’ nothingness to fill it up with something again. It’s not quite cricket (though the rules are almost as complicated). So perhaps Mexicans should prepare for the Uarhukua hooligans.

• WHEN Kahlo first donned the traditional peasant costumes that became her trademark, she did so with all the awareness of a nun taking the veil. She was claiming a new identity. Her clothes were an integral part of her persona, as the Tate curator Tanya Barson understood only too well. When one of Frida’s old friends casually suggested that she might like to try on a costume that had belonged to the artist, Tanya (who, having spent 18 months preparing for the Tate’s Frida show, might have worried that this woman had already taken up quite enough of her life) looked at once stricken and awestruck. But, though peasant garb won Frida, the bourgeois-bohemian, individual attention, this has not worked for its traditional wearers.

  The most haunting sight that I saw in Mexico City was a nude demonstration. Hearing it talked about, it had sounded amusing. But then suddenly I saw them: Mexican peasants dispossessed of their land standing stripped at the base of a traffic-island monument. They had resorted to nakedness in a last-ditch attempt to get government attention. Nothing was all they had left.

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