<P> George III (George William Frederick; 4 June 1738--29 January 1820) was King of Great Britain and King of Ireland from 25 October 1760 until the union of the two countries on 1 January 1801, after which he was King of the United Kingdom of Great Britain and Ireland until his death . He was concurrently Duke and prince - elector of Brunswick - Lüneburg ("Hanover") in the Holy Roman Empire before becoming King of Hanover on 12 October 1814 . He was the third British monarch of the House of Hanover, but unlike his two predecessors, he was born in Britain, spoke English as his first language, and never visited Hanover . </P> <P> His life and with it his reign, which were longer than any other British monarch before him, were marked by a series of military conflicts involving his kingdoms, much of the rest of Europe, and places farther afield in Africa, the Americas and Asia . Early in his reign, Great Britain defeated France in the Seven Years' War, becoming the dominant European power in North America and India . However, many of Britain's American colonies were soon lost in the American War of Independence . Further wars against revolutionary and Napoleonic France from 1793 concluded in the defeat of Napoleon at the Battle of Waterloo in 1815 . </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> <P> Historical analysis of George III's life has gone through a "kaleidoscope of changing views" that have depended heavily on the prejudices of his biographers and the sources available to them . Until it was reassessed in the second half of the 20th century, his reputation in the United States was one of a tyrant; and in Britain he became "the scapegoat for the failure of imperialism". </P>

Who was known as the mad king of england