Isadora Duncan, regarded as the mother of modern dance, was equally unfettered in her art and in her personal life.

Shortly after Duncan’s birth in San Francisco in May 1877, her father’s bank crashed, and he abandoned his wife and four children. Raised in a free-thinking atmosphere by her atheist mother, Duncan was always a rebel. Having learned to dance by watching the rhythm of the ocean, she left school in her early teens and made money teaching dance lessons to other youngsters. After beginning her dance career in Chicago and New York in the late 1890s, Duncan traveled with her family to London, where she soon garnered considerable acclaim.

In 1900, Duncan moved to Paris and became part of the Montparnasse artist community. Over the years she met dozens of celebrated bohemians, artists, and political radicals —many of them queer. On Long Island in 1917, she made friends with actress Sarah Bernhardt and writer Mercedes de Acosta, notorious for her public lesbian affairs with stage and screen stars. In the 1920s, Duncan socialized with a circle of American expatriate lesbians that included Natalie Barney, Djuna Barnes, Janet Flanner, and Gertrude Stein.

Duncan eschewed the constraints of classical ballet, developing her own style of fluid, expressive movements inspired by nature. She likewise rejected traditional ballet costumes, preferring flowing tunics, long scarves, and bare feet to tutus, tights, and toe shoes. Influenced by the poetry of Walt Whitman, the philosophy of Friedrich Nietzsche, and the drama of classical Greece, Duncan regarded dance as a sacred art. "The dance is a religion and should have its worshippers," she once said. Believing that art and movement should be part of every child’s education, she established dance schools in Germany, France, England, and Russia.

Her pioneering style did not escape criticism, especially in America. Classical choreographer George Balanchine once called her "a drunken fat woman who for hours was rolling around like a pig."

Duncan’s personal life was as controversial as her art. She became emblematic of the New Woman of the early 20th-century wave of feminism, challenging Victorian prudery and Puritan notions of propriety. "If my art is symbolic of any one thing," Duncan once said, "it is symbolic of the freedom of woman and her emancipation from hidebound conventions."

Having vowed at age 12 never to marry, Duncan was a free-love advocate in theory and in practice. She had countless affairs, mostly with men but apparently also with some women. She had two children out of wedlock, a daughter with stage designer Gordon Craig and a son with sewing machine heir Paris Singer (though she resisted the advances of his sister, Winaretta). In 1913, Duncan’s children drowned when the car in which they and their governess were riding rolled into the River Seine as the chauffeur stepped out to crank the engine. In her grief, Duncan sought comfort in Italy from renowned stage actress Eleonora Duse, with whom she is rumored to have had an affair.

Duncan embraced Communist politics around the time of the 1917 Russian Revolution, declaring Europe to be "hopelessly bourgeois." In 1922, she married Sergei Esenin, an unstable bisexual Russian poet nearly 20 years her junior (a relationship that would last barely a year). During her final U.S. tour that October, in the midst of America’s first Red Scare, Duncan bared her breasts on stage in Boston and, waving a crimson scarf, proclaimed, "This is red! That is what I am!" Mayor James Curley promptly banned her from the city. "Why should I care what part of my body I reveal?" Duncan said in her defense. "To expose one’s body is art; concealment is vulgar."

By the mid-1920s, Duncan’s ambitious projects and reckless spending habits had left her reliant on the charity of friends. In 1926, Mercedes de Acosta came to Duncan’s rescue, paying off her debts and pressuring her to complete her autobiography to earn some money. In their respective memoirs, neither woman explicitly revealed whether their liaison was sexual, but clues can be found in the passionate letters and poems Duncan wrote to de Acosta: "My kisses like a swarm of Bees / Would find their way / between thy knees / & suck the honey / of thy lips / Embracing thy / Two slender hips." Alice B. Toklas said that de Acosta "had the three greatest women of the 20th century," including actresses Greta Garbo and Marlene Dietrich; many believe the unnamed third woman was Duncan.

Duncan died in a freak automobile accident in Nice on September 14, 1927. Flirting with a young garage mechanic, she demanded a ride in his convertible sports car. Duncan’s long shawl became entangled in the car’s rear wheel, yanking her from the vehicle and breaking her neck. As if predicting her fate, she had shouted just before the car took off, "Adieu, mes amis, je vais à la gloire!" ("Goodbye, my friends, I go to glory!")