In The Madness of King George, George III (Nigel Hawthorne) begins to behave in an odd manner thirty years into his rule over England, shouting obscenities at people, spouting garbled rubbish and attacking his wife's young Mistress of the Robes, Lady Pembroke (Amanda Donohoe).

The Prince of Wales (Rupert Everett) is determined to see that his father is declared unfit to rule so he can become Regent and denies him access to those close to him. The Prime Minister is forced to intervene and sends his own doctor to help the King, instead of the Prince's doctors, and the King eventually begins to regain his sanity.