Edie Sedgwick: The It girl who was inspiration to Dylan and Warhol

To some, she was a just a society heiress who did a lot of drugs. But to Andy Warhol and Bob Dylan, Edie Sedgwick was a muse - a wild blonde superstar who defined the look and excesses of the Sixties. As Sienna Miller prepares to portray her in a forthcoming film, Andrew Wilson tells the story of a short yet extraordinary life

The peculiar-looking man with a shock of platinum blond hair stood on the margins of the room, transfixed by the spectacle in front of him. The etiolated young woman, dancing in an idiosyncratic fashion, freely mixing classical ballet poses with rock'n'roll, basked in the attention as she continued to move in a way that observers described as almost Egyptian.

When the couple - pop artist Andy Warhol and 21-year-old socialite Edie Sedgwick - started talking later that night, at the apartment of a New York advertising executive, they began one of the most iconic, and controversial, creative partnerships of the post-war era. During the mid-Sixties Sedgwick, as one of the Factory "superstars", featured in 12 short films directed by Warhol; experimental works such as Vinyl, Space, Restaurant, Kitchen, Chelsea Girls and Outer and Inner Space. And through her appearance in fashion magazines and newspapers, with her crop of dyed blonde hair, kohl-rimmed eyes, gamine figure and her fondness for black tights, she spawned a whole new look.

That style continues to influence designers today (Galliano named her as his muse for his 2005 Dior collection). And the current buzz in the publishing and movie world suggests that she may have a deeper cultural relevance too. Not only is a biography of the model and actress, who died in 1971 age 28, about to be re-issued, but a new film, Factory Girl, starring Sienna Miller as Edie, Guy Pearce as Warhol and Hayden Christensen as a character loosely based on Bob Dylan, is set for release at the end of the year. What is it about this fragile and tragic figure that continues to inspire such interest?

Edith Sedgwick was born in April 1943 in Santa Barbara, California, and grew up surrounded by the spoils of wealth and privilege; her ancestors were the nearest thing to American aristocracy. Yet her father, Francis, known as "Duke" or "Fuzzy", had experienced problems with mental illness as a child and, after a breakdown brought on by manic depression, he was advised by a psychiatrist never to have any children; Francis and his wife Alice went on to have eight.

Edie, the couple's seventh child, was named after her father's favourite aunt, Edith Minturn Stokes, a society beauty painted by John Singer Sargent. Her sense of drama was probably inherited from her grandfather, Henry Dwight "Babbo" Sedgwick, who - when informed by his sweetheart that she would not marry him - tried to shoot himself. Fortunately, he had the wrong ammunition and the marriage duly went ahead. According to his grandson Harry Sedgwick, although Babbo wrote 30 books, mostly biographies and history, "his real career was his life... He closed one of his letters to me, 'Squeeze the flask of life to the dregs'."

From an early age, Babbo's granddaughter Edie devoted herself to nothing else. As a baby, her nursemaid recognised that she had a will of her own and, according to her elder sister Saucie, the child "grew up with a total lack of boundaries, a total lack of a sense of scale about her". At the family's ranch in California, where oil was discovered in the early Fifties, making the Sedgwicks even richer, Edie could gaze across to the horizon and know that all the land she saw belonged to her parents. "Imagine a situation like that where nobody entered who wasn't invited or hired," said Saucie.

The children viewed their parents, especially their father, like Greek gods, physically perfect, distant figures. "The tragedy was that, along with their happiness and their incredible appetite for life, the forces of darkness were always there, although you would never have known it: the surface looked so good," Saucie told Edie's biographer Jean Stein. "So it was a life of extremes - paradise and paradise lost."

According to Edie, her father tried to sleep with her when she was seven years old, and one of her brothers attempted to seduce her. "Nobody told me that incest was a bad thing or anything, but I just didn't feel turned on by incest," she said later. One day, Edie came across her father having sex with another woman. The girl became hysterical and, although she tried to tell her mother about her father's infidelity, nobody believed her. Francis accused her of inventing the whole episode and called a doctor, who prescribed tranquillisers for her. The incident had a profound effect on her, as it gave her a taste for drugs and forced her to question her own reality.

At school she developed anorexia and bulimia, and her mental state was further disturbed when she learnt that her elder brother Minty, an alcoholic by the time he was 15, had been committed to Silver Hill, a psychiatric institution in Connecticut, after bouts of erratic behaviour. In the autumn of 1962, after her father threatened to leave the family if she wasn't institutionalised, Edie too was placed in Silver Hill. For a time, the treatment seemed to help her, but then, towards the end of her stay, she became pregnant and decided to abort the baby.

"I could get an abortion without any hassle at all, just on the grounds of a psychiatric case," she told David Weisman, director of Edie's last film Ciao Manhattan. "So it wasn't too good a first experience with lovemaking. I mean, it kind of screwed up my head, for one thing." By autumn 1963 she had enrolled at Cambridge, Massachusetts, to study art. Almost ghostlike in her paleness, the waif-like figure started to gather around her a coterie of friends, particularly gay men. She frequented the Ritz in Boston, where she would entertain her little audience of new friends by singing Richard Rodgers' "Loads of Love". "I want some money, and then some money, and loads of lovely love," went the lyrics. Although her wealth was bountiful - she came into her inheritance on her 21st birthday - the latter was in short supply.

In order to compensate for this she sought out an audience wherever she went. She adored the fact that people noticed her when she walked into a room. "She was voracious for people," said Chuck Wein, a friend from Harvard who took on the role of Edie's promoter. "It got everybody off their boring number. Here was this glamorous freak. People were willing to let Edie be the star." She dropped out of Cambridge and moved to New York in the summer of 1964, hoping to get some work as a model. She moved into her grandmother's East Side apartment and drove her stylish grey Mercedes around town - sometimes dropping acid as she did so - until she crashed it. From then on, she travelled around Manhattan by limousine. It seemed as though she was determined to make something of herself, to construct an identity that was almost fictional in its extremity.

The deaths of her two brothers - first Minty, who was most likely homosexual and who committed suicide in March 1964, and then Bobby, in a motorbike accident January 1965 - had unbalanced her; yet the loss also made her more determined to live her life at an even more intense pace, as if she knew that she would not have much time left herself.

Warhol cohort Chuck Wein had already told Andy that he should meet Edie. Wein suggested to the artist that his existing "superstar" Baby Jane Holzer, who was featured in his 1964 films Couch and Batman Dracula, was "running out of speed" and that he should replace her with Edie. When the pair finally met, in January 1965, the attraction was instant and Edie started to spend more time at Warhol's Factory, that hothouse of creative anarchy with its foil covered walls, on East 47th Street. Soon Edie started to dress like Andy. She cut her hair into a boyish crop and dyed it blonde. Andy, meanwhile, projected fantasies of his own on to her.

"I think Edie was something Andy would like to have been; he was transposing himself into her à la Pygmalion," claimed Truman Capote. "Andy Warhol would like to have been Edie Sedgwick. He would like to have been a charming, well-born debutante from Boston. He would like to have been anybody except Andy Warhol."

The collaboration made Edie famous. She featured in a Vogue magazine shoot, in which she was dubbed a "youthquaker" and, in October 1965, she was nearly mobbed by college students shouting, "Edie and Andy!" at Warhol's exhibition at the Institute of Contemporary Art in Philadelphia. The space in front of a camera seemed like her natural home; friends told Edie that she could be a famous star like Garbo or Monroe and, while she believed it to be possible, she refused to go to Hollywood. Drugs were just as big an addiction as fame and she soon became hooked on speed, cocaine and heroin. "That was the first time I had a shot in each arm. A shot of cocaine and speed, and a shot of heroin. Stripped off all my clothes, leapt downstairs, and ran out on Park Avenue and two blocks down it before my friends caught me. Naked. Naked as a lima bean."

Throughout this, Edie retained her extraordinary looks; Vogue editor Diana Vreeland said she had lovely skin, but then she said every drug addict she had ever seen had wonderful skin. Edie's presence was magnetic, remembers John Cale, co-founder of The Velvet Underground who had a six-week affair with her. "Although desperate and on her last legs with Andy, she still possessed all the elemental magic, frayed beauty and presence of Marilyn Monroe."

In 1966, after meeting and becoming infatuated with Bob Dylan, Edie told Warhol that she had signed a contract with the singer's manager. Warhol was angry that she had left his artistic stable and, perhaps to get his revenge, told her the truth that Dylan - who, it is rumoured, wrote the songs "Just Like A Woman" and "Leopard-Skin Pill-Box Hat" about her - was married. In October 1966, she took one line too many, fell unconscious and woke up to find her apartment on fire. After coming out of hospital, Edie told a friend "I have an accident about every two years, and one day it won't be an accident."

She moved into the Chelsea Hotel and embarked on a relationship with Dylan's friend, the musician, Bob Neuwirth. "I was like a sex slave to this man," said Edie in the tapes made during the filming of Ciao Manhattan. "I could make love for 48 hours... without getting tired. But the moment he left me alone, I felt so empty and lost that I would start popping pills."

After that relationship ended she went downhill. Her drug use continued to spiral and she spent more and more time in psychiatric institutions. By the time she next saw her brother Jonathan, in 1968, she was so wasted she could not walk, and was so out of control that she suggested they have sex together. She was arrested for drug possession in 1969 and sent to Cottage Hospital in Santa Barbara, the place where she had been born. There she met fellow patient Michael Post with whom she fell in love. "I've really been to the depths, but now I want to start a new life," she said. However, her addiction to fame - and to drugs - proved all-consuming.

Edie continued to shoot Ciao Manhattan, David Weisman's experimental film about her life that he had started in 1967. Rather awkwardly she had had a breast augmentation in the intervening years. In the movie, this is explained in the following exchange. One character turns to Edie and says, "Goddam, your tits sure did get bigger since then," to which the actress replies, "Yeah, I eat better now and I do my exercises." During the filming, Edie had problems with her lines and her mental state degenerated to such an extent that she had to have electric shock therapy, a process she had earlier enacted for Ciao Manhattan. After five months in an institution, she emerged to get married to Michael Post in July 1971.

On the night of 15 November 1971, Edie went to a fashion show at the Santa Barbara Museum where, attracted by the cameras, she was filmed as part of a television programme called An American Family. Afterwards, at a party, she was verbally attacked by a female guest, who accused her of being a heroin addict. Later that night, Michael gave his wife her medication but, the following morning, he woke to find her cold and stiff beside him. An autopsy revealed that she had died from a barbiturate overdose and the coroner recorded a verdict of accidental death/suicide.

According to Factory Girl director George Hickenlooper - whose previous credits include Hearts of Darkness, a documentary about the making of Apocalypse Now - Edie was a universally tragic figure. He sees her as symptomatic of a particularly American phenomenon: "I think Americans suffer from something that's called acute abandonment anxiety, which means they're looking for love outside the family," he says. "[It is] that whole phenomenon of celebrity and fame where people look to be loved by the public because they can't find love at home. And Edie sort of epitomises that."

To some Sedgwick's achievements may appear to be trifling - a couple of fashion spreads in US Vogue, a clutch of roles in Warhol's underground movies and an astounding talent for partying, drug-taking and marathon sex sessions. Sienna Miller herself has described Sedgwick as "an anorexic, speed-freak nut-bag". Meanwhile, actress Chloë Sevigny says: "People always make reference to her when they write about me. And I find it a little offensive, because she was just a rich society girl who did a lot of drugs and didn't accomplish much."

Yet to dismiss her in this way is to overlook the very modern notion that she constructed her life as if it were a piece of performance art, a fact that was acknowledged by serious artists at the time. Roy Lichtenstein regarded Warhol and the Factory set as a work of living art, while Robert Rauschenberg, who met Edie at an opening, said that he always felt intimidated by her, "because she was like art. I mean, she was an object that had been very strongly, effectively created".

Edie was buried in Oak Hill Cemetery, Ballard, a place described by her sister Saucie as a backwater - "no one would go there except to see the veterinarian," she said. Her gravestone, a simple slab of polished red granite, is very different from the imposing structures that mark her family's plot in the Sedgwick burial place in Stockbridge, Massachusetts. An oft-told story, repeated at family gatherings, was how on a summer's evening it was possible to hear the crickets in the graveyard singing "Sedg-wick, Sedg-wick". However, in our celebrity obsessed culture, it is more likely that they are calling out for Edie, than for any of her more respectable, upstanding forebears. m

'Edie: An American Biography' by Jean Stein, edited with George Plimpton (Pimlico, £8.99) is out on 6 April. 'Factory Girl' is out later this year