She's been toyed with, traumatized, heartbroken and betrayed. She's been praised for being vulnerable — and pilloried for being a village idiot. Since her story was first performed in 1841, the ghostly, lovelorn character of Giselle has flitted her way across stages from Melbourne to Moscow and drawn interpretations that have placed her in settings ranging from a mystical glade to a mental asylum. But whatever her personal failings, the ballet of her life, death and afterlife has retained its appeal for ballet companies, dancers and audiences for more than 150 years. "There's something eternal in the basic narrative," says John Neumeier, artistic director of the Hamburg Ballet, which is staging a Giselle gala this summer. "A woman who's very pure and trusting and in the end very strong, and a man who's made a great mistake."

Neumeier's Giselle in Hamburg is just one of several that can be found across Europe this summer. In Milan and London, French ballerina Sylvie Guillem, appearing as a guest artist with La Scala Ballet, is both co-choreographer and prima ballerina in productions at La Scala and Covent Garden. Giselle is also being performed in Budapest at the Hungarian State Opera House. Each of the versions will doubtless present something different: the Hamburg version will be performed in more modern dress, with sparse stage decoration. "You can take all sorts of liberties," insists David Bintley, artistic director of the U.K.'s Birmingham Royal Ballet, whose own version of Giselle had the characters dressed in garishly bright costumes, and whose story lent additional depth to some of the minor characters, like Giselle's mother. "That the piece can survive all of that intact is a measure of its greatness."

Giselle was conceived by French author and critic Théophile Gautier, to provide a showcase for the ballerina Carlotta Grisi. The initial success of the ballet, which was first performed in Paris in 1841, led to performances in London and St. Petersburg in 1842 and Milan in 1843. It's a simple enough story: Giselle, a frail young peasant girl, dies after she finds out that her lover Albrecht — who is from a much higher rung on the social ladder — has deceived her. She re-emerges as a ghost among the Wilis, a group of rejected women who prey on lovers that have let them down. Yet when a remorse-filled Albrecht visits her grave, Giselle saves his life by protecting him from the Wilis.

To modern ears the plot may sound implausible — although perhaps no more implausible than a prince being smitten by a woman who is also a swan, as happens in Swan Lake. But to its first audiences, the idea of bitter female ghosts, crazy with grief and the wrath of the scorned, "was frightening," says Sheila Dickie, community and education officer at Sadler's Wells Theatre. "That's what Giselle was meant to be."

Even if Giselle moves modern audiences less to terror than to sympathy, there are still several parts of the ballet that are emotionally very challenging. In the first act, when Giselle discovers the extent of Albrecht's betrayal, she has a "mad scene" in which she flits and flails wildly across the stage. And her pas de deux in the second act with the regretful Albrecht is one of the most poignant to be found in the romantic ballets.

Both are great challenges to a dancer, and for this reason, prima ballerinas want to dance Giselle. It's a part that can make or break careers. "It's a very difficult role technically," says Dickie. "And you also need to get the audience's sympathies. Often dancers are brilliant, but they can't get to the heart of the audience." Earlier this year, Alina Cojocaru, 20, a Romanian dancer, was promoted to a principal dancer at Britain's Royal Ballet after just two performances of Giselle. "It's considered the same as Hamlet is considered for the Shakespearean actor," says Dame

Alicia Markova, a former prima ballerina who in 1960 wrote a book titled Giselle and I. "You have to be something almost not human to give a good rendering, because it demands so much. Wherever I went, that's what the people asked for."

Contemporary audiences have found themselves on the receiving end of a wide range of interpretations. The Harlem Dance Company did a version that placed Giselle in the southern U.S. The Cullberg Ballet, a Swedish company, presented a Giselle in which the main character did not die but instead went off to a mental asylum. Critics praised some of the adaptations as innovative, but not everyone is impressed. "It must be Giselle's spirit that converts Albrecht," insists Neumeier, who says that the ballet loses an essential element if Giselle does not die. "It's like Romeo and Juliet not dying. I mean, do we really want to see them when they're 65?" Markova concurs. "Why can't they just leave a great classic as it is?" she says in a voice laced with exasperation. "You don't take a great classic and turn it. You come up with proper new ideas." But with a story as intriguing as Giselle, the ballet world may find it hard to break away.