George III, King of Great Britain

George III was the longest-reigning king (1760-1820) in British history. He had many titles, including King of Great Britain and Ireland. Third of the British Hanoverian monarchs, he was the first to be born in England and to use English as his first language.

According to the official web site of the British Monarchy: "The American war, its political aftermath and family anxieties placed great strain on George in the 1780s. After serious bouts of illness in 1788-89 and again in 1801, George became permanently deranged in 1810."