George III was the King of Great Britain and King of Ireland from 1760 until his death in 1820. He is known for his long reign, which included the American Revolutionary War and the Napoleonic Wars. George III's reign was marked by political and social unrest, and he is often remembered for his struggles with mental illness in his later years. Despite his personal challenges, George III was a significant figure in British history and his reign had a lasting impact on the development of the British Empire.