Anastasia, Royal Opera House

Kenneth Macmillan's Anastasia is a ballet, and a heroine, torn between two worlds. Its heroine is Anna Anderson, the woman who believed she was the Grand Duchess Anastasia. It hardly matters that DNA testing has since proved her wrong; the ballet is about the violent loss of identity.

Kenneth Macmillan's Anastasia is a ballet, and a heroine, torn between two worlds. Its heroine is Anna Anderson, the woman who believed she was the Grand Duchess Anastasia. It hardly matters that DNA testing has since proved her wrong; the ballet is about the violent loss of identity.

The one-act version of the ballet, made in 1967, is a jagged, expressionist dance to Martinu's Sixth symphony. Film of the Imperial family flickers around Anastasia as she waits in an asylum. In 1971, MacMillan added two acts, set to Tchaikovsky symphonies: Anastasia's memories of the golden world destroyed by the revolution.

Leanne Benjamin dances powerfully as Anastasia, but she doesn't quite carry the ballet. In the first two acts, MacMillan gives her an odd little gesture, hands to shoulders, the tomboy child settling her collar. As Benjamin repeats that gesture, you can see that it's characteristic, and you don't miss the changing emotion behind it. But she doesn't draw you into the heroine's dilemmas. Steps and drama are always strong and clear, but she hasn't yet got under Anastasia's skin.

The Martinu act is the strongest in the ballet, a powerful image of confusion and, as Anastasia draws herself together, of resolution. Those Tchaikovskies are more problematic. MacMillan sometimes strains to fill these expansive scores.

The first act, an idyll on the Imperial yacht, marks time while the music finishes its patterns. The second shows a grand ball for Anastasia's coming-out. As the court circle, MacMillan starts to pick out relationships among them. The Tsar's favourite ballerina, sweeps in, ready to make an impression. Miyako Yoshida is elegant, while Johan Kobborg is a dashing partner, all smooth line and clean-cut beaten steps.

Before his death in 1992, MacMillan considered expanding the role of Rasputin for Irek Mukhamedov. His widow Deborah MacMillan has adapted the last act on those lines, making Rasputin a more prominent figure in Anastasia's memories. I suspect it's made little difference: Rasputin is still a shadowy figure at the edges, not really a role. The world of Anastasia isn't consistently realised, but it comes to life in lucid moments and supporting performances. Joshua Maloney's Tsarevitch is a believably sulky little boy. Edward Watson is warmly protective as Anna Anderson's peasant husband.

As the Tsarina, Rosato makes even accidental gestures part of the drama. In the ball scene, an ornament came loose on Benjamin's gown. Rosato, picking it up, made the moment part of her daughter's coming-of-age. A touch on Benjamin's arm urged her into the dance; a smile to the Tsar acknowledged this mother's need to protect her child, and to let her go.