Isadora: The Sensational Life of Isadora Duncan by Peter Kurth

Shooting bullets at the ballet

Born in 1877 in San Francisco, Isadora Duncan led an uncharmed but exemplary life. In 50 years, she saw and did as much as any of her artistic peers. Her triumphs and discontents resonated across four continents, and she settled in New York, Athens, Paris, London, Berlin and Moscow.

Many have written of the woman who invented modern dance with her "natural" movement and revolutionised traditional ballet, which she considered "an expression of degeneration". Of those authors, Isadora alone was not enthralled by her subject. Shortly before her death, compelled by poverty, she allowed the ghost-writing of her own version – My Life, which sought to reclaim her youthful idealism. Cables from New York pleaded: "Enough of your highfalutin ideas. Send love chapters. Make it spicy."

They had a point. Isadora's erotic life was extraordinary. Once initiated sexually at 25, she – characteristically – converted absolutely. There were hundreds of men, probably a few women and long affairs with Gordon Craig, son of Ellen Terry, and Paris Singer, the astonishingly rich sewing-machine heir, whose proposal she refused.

Disastrously, at 44, Isadora took on the crazed Russian poet Sergei Esenin, 18 years her junior. They married to get Esenin out of Russia. In return, he beat Isadora – "he was a great poet, even if he did knock me about" – and learnt two non-Russian words, "genius" and "kaput". The first he applied exclusively to himself; the second, to everything else. America he proclaimed "enough to make one hang oneself". Four years later, he did so – in Russia. Isadora might again have solved her financial difficulties as heir of his estate. She refused the money.

Like Cleopatra, Isadora embodied contradiction. Hers was a reactive temperament. Impressionable and capricious, she lacked intellectual rigour and was unmoved by the ethical and practical concerns that preoccupy others. Greenwich Village intellectuals lauded her feminist credentials after her children were born out of wedlock. On one occasion, reading Nietzsche led her to insist that "all the women must be put back again into Harems."

A thoroughgoing racist, Isadora railed against "the tottering, ape-like convulsions" of jazz dancers, "wriggling from the waist downwards" in erotic suggestiveness. Of Argentinian critics, Isadora concluded: "They are niggers. They understood nothing." When her career demanded it, she happily toured the Maghrib, however. "She sees the future of the dance in Africa," noted one fellow traveller.

Isadora's performances outraged the puritanical, as jazz shocked her. In Vienna, Princess Metternich asked Loie Fuller: "Why does she dance so insufficiently clothed?" Fuller dissembled: "I forgot to tell you how amiable our artiste is. Her baggage has not yet arrived, but rather than disappoint us here today, she has consented to appear in her practising costume." Boston audiences were horrified at the repeatedly exposed breasts. Later, naive Bolshevism in Isadora's post-performance speeches shocked America more comprehensively.

The Berliner girls at Isadora's first school learnt English by way of Keats. Her charisma and early stage successes bewitched many of these "Isadorables". Ultimately, just one, Irma, was conspicuously loyal. There was a downside to the possessive hold. Anna, one of the six she semi-legally adopted, aptly commented that Isadora "could not cope with advancing age".

She sought to prevent her best pupils from displaying their talents – especially when, appearing alongside her, they highlighted her declining powers. "Like Peter Pan, you must not grow up!" she insisted. In this light, her frequent comparison of dance to Rodin's statues feels sinister. Practical tuition was left to another, less impatient Duncan – Isadora's lame sister, Elizabeth.

Peter Kurth is no dance specialist. But he intelligently synthesises the many views of Isadora's practice. The absurd in much she did is exposed, too. Appearing at Bayreuth, she insulted Cosima Wagner with the line: "The Master's mistakes were as great as his genius." Reaching Greece, Isadora forsook "the high-heeled shoes of a decadent civilisation"' and adopted – to ridicule – the tunic of the ancients.

Isadora resembles Jean Brodie with added wanderlust and the ambition to educate not just a few, but an entire world. Ambivalent about motherhood, she recognised how childbirth would ruin her looks: "It was strange to see my beautiful marble body softened and broken and stretched and deformed... Where was my lovely, youthful, naiad form?" But Isadora adored her two children, never recovering from the shock when they were drowned, at six and three, in a freak car accident.

The subsequent artistic rendering of her suffering chimed with a world of vast social change, and one – from 1914 – at war. Though indulgence bloated her (she drank mostly champagne, always to excess), for some Isadora remained magical. To others, her late appearances were farce. Diaghilev noted approvingly in 1904 that her St Petersburg début gave Russian ballet "a shock from which it could never recover". The young Balanchine, however, was appalled in 1924 at the "drunken, fat woman who for hours was rolling around like a pig."

Isadora acknowledged her waning powers: "I don't dance any more. I only move my weight around." Her humour in confronting accelerated decline is touching. When asked which lovers had hurt her, Isadora quipped: "Sometimes I thought my heart was broken, but it was only bent." At 50, she was strangled when her shawl became trapped in the wheel of the car driven by her latest fling. Cocteau called the accident "perfect... a kind of horror that leaves one calm."

Small errors mar this book. Kurth misquotes Whitman; Venice's Basilica becomes the "Cathedral of San Marco". There's an occasional failure of tone, too, as in these broad brush strokes: "This was the era of the table-rappers, of theosophy and Christian Science, but it was also the era of Darwin." Still, there can be no definitive Isadora. For one thing, her legend was preserved by her shrewd refusal to be filmed dancing. This is a worthy portrait for our times – an Isadora both impossible and irresistible, like Vanessa Redgrave in the film of 1968 and, later, Martin Sherman's play When She Danced. As mythical today as the figures she revered in Greek drama, Isadora eludes final capture. But Kurth offers us a clear and probable likeness.

Richard Canning is writing a biography of Ronald Firbank