<P> In the later part of his life , George III had recurrent , and eventually permanent , mental illness . Although it has since been suggested that he had the blood disease porphyria , the cause of his illness remains unknown . After a final relapse in 1810 , a regency was established , and George III 's eldest son , George , Prince of Wales , ruled as Prince Regent . On George III 's death , the Prince Regent succeeded his father as George IV . </P>
<P> In the later part of his life , George III had recurrent , and eventually permanent , mental illness . Although it has since been suggested that he had the blood disease porphyria , the cause of his illness remains unknown . After a final relapse in 1810 , a regency was established , and George III 's eldest son , George , Prince of Wales , ruled as Prince Regent . On George III 's death , the Prince Regent succeeded his father as George IV . </P>
who was known as the mad king of england
who was known as the mad king of england
George III
George III