George III's behaviour has often been odd, but now he is deranged, with rumours circulating that he has even addressed an oak tree as the King of Prussia. Doctors are brought in, the government wavers and the Prince Regent manoeuvres himself into power. Alan Bennett's play explores the court of a mad king, and the fearful treatments he was forced to undergo. It is about the nature of kingship itself, showing how by subtle degrees the ruler's delirium erodes his authority and status.