Which illness plagued England's King George III for most of his life?

George III was monarch of Great Britain and Ireland from 1760 till 1820. He was the son of Frederick Louis, prince of Wales, and Princess Augusta of Saxe-Gotha. The young George harbored an unreasonable dislike of his grandfather, King George II.

George was a slow-learner and could not read properly until after age 10. His father died, leaving him heir to the throne at 12. It is clear that, in beginning with his 18th birthday to prepare conscientiously for his future responsibilities, he tormented himself with thoughts of his inadequacy.

He suffered several episodes of mental illness during his life, perhaps even as early as 1765. In 1788, he experienced a truly severe case of psychosis. He is reported to have spoken nonstop for hours on end, to the point that his voice went raspy and he foamed at the mouth.

George's doctor encouraged a regime of manual labor and fresh air. Other tactics used by the king’s physicians included restraining George until he was calm.

Initially, the treatment seemed to work, but the king had several subsequent mental health re-occurrences. In 1810, George had a major breakdown that doctors were unable to cure and his son took over as regent.

George eventually died in 1820. Researchers at the University of London studied the king’s letters and believe that there is conclusive evidence that he suffered from “acute mania,” an excitable, hyperactive condition that could resemble the manic phase of what is known as bipolar disorder.