King George III of England (Nigel Hawthorne) is a monarch who is at heart a family man. His Queen, (Helen Mirren) is a simple soul at heart, too. Their son, the foppish Prince of Wales (Rupert Everett) is only too eager to manipulate events when his father suffers from what his contemporaries refer to as madness. The King starts by shouting obscenities and assaulting one of his Queen's ladies-in-waiting; a complete personality change which mystifies his doctors. The Prince of Wales rallies politicians in support of his bid to succeed to the throne. The film documents the King's partial recovery by means of savage and often humiliating medical treatments.