The drama follows from Shaw's longstanding need to reimagine Shakespeare's work, epitomised by his play Caesar and Cleopatra and his late squib Shakes versus Shav.

Shaw removes the implausible account of the British victory over the Roman legions, which in the original is achieved purely by the superhuman heroism of Posthumus, Polydore and Cadwal.

He replaces it with a conversation in which the Romans discuss the possibility that the Britons recalled Belarius, a general who "knew his job", to command their forces.

Paradoxically Shaw offered his own alternative ending as challenge to producers to restore Shakespeare's original, which had been crudely cut in many productions.

Young notes that there is "a violent change of tone from the fairy-tale and romantic atmosphere of the original acts to the Shavian wit with a touch of cynicism, of the end.