Stage biographies have their perils, the greatest of which is probably the comparison with a good written version that can convey much more information and analysis.

In the case of Simon Callow, all hurdles have been cleared by a soaring interpretation that combines a balanced narration with a sensitive embodiment of Charles Dickens, his subject. He proves to be the subtlest of actors. He opens and continues for a time on a quiet note, providing a narration replete with interesting detail.

We are taken into the poverty and vicissitudes of the Dickens family, studded with emergencies and a grinding work spell for the 12-year-old boy, the scars from which never left him. His father became the model for Micawber, in David Copperfield, his mother for Mrs Nickleby; a unique and memorable therapy.

As the story proceeds, the actor increasingly unveils his comic and interpretative skills. A compulsive worker who drove himself to a premature grave, Dickens created a familiar host of immortal characters.

It is fascinating to follow the private agonies in parallel with the writings, which brought the author fame from his mid-20s. He married about then, and had 10 children by a wife whom he came to loathe - in common with his mother and sisters. Talk about angst.

Dickens was, among many other creative things, a considerable actor, and the time came when he went on reading tours, playing his creations, to great acclaim and reward. Towards the end, when his health was broken and his psyche in deep trouble, he sought, as always, refuge in work and, fatally, embarked on yet another such tour. Callow here reaches new heights of comedy and versatility as he plays the author playing the characters, a rara avis of a double take.

An inevitable dying fall is beautifully modulated and a real theatrical experience consummated. The actor is the beneficiary of a fine script by Peter Ackroyd and of Patrick Garland's direction, together with atmospheric design and lighting, but to him be the spoils.

Runs until Saturday