George III of the United Kingdom
George III (born George William Frederick; June 4, 1738 – January 29, 1820) was King of Great Britain and King of Ireland from October 25, 1760 until January 1, 1801, and thereafter of the United Kingdom of Great Britain and Ireland. He was concurrently Duke of Brunswick-Lüneburg, and thus Elector (and later King) of Hanover. The Electorate became the Kingdom of Hanover on October 12, 1814. He was the third British monarch of the House of Hanover, and the first of Hanover to be born in Britain and speak English as his first language. In fact, he never visited Germany.
George III's long reign was marked by a series of military conflicts involving his kingdom and much of the rest of Europe. 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 its American colonies were soon lost in the American Revolutionary War, which led to the establishment of the United States. Later, the kingdom became involved in a series of wars against revolutionary and Napoleonic France, which finally concluded in the defeat of Napoleon in 1815. In addition, during George's reign the realms of Great Britain and Ireland were joined, forming the United Kingdom.
Later in his reign George III suffered from recurrent and, eventually, permanent mental illness. This baffled medical science at the time, although it is now generally thought that he suffered from the blood disease porphyria. Recently, owing to studies showing high levels of the poison arsenic in locks of King George's hair, arsenic is also thought to be a possible cause of King George's insanity and health problems. After a final relapse in 1810, his eldest son, George, Prince of Wales ruled as Prince Regent. On George III's death the Prince of Wales succeeded his father, as George IV. George III was the grandfather of Queen Victoria.