Aging King George III of England (Sir Nigel Hawthorne) is exhibiting signs of madness, a problem little understood in 1788. As the monarch alternates between bouts of confusion and near-violent outbursts of temper, his hapless doctors attempt the ineffectual cures of the day. Meanwhile, Queen Charlotte (Dame Helen Mirren) and Prime Minister William Pitt the Younger (Julian Wadham) attempt to prevent the King's political enemies, led by the Prince of Wales (Rupert Everett), from usurping the throne.