Portal:United Kingdom/Featured biography/104

George III was King of Great Britain and King of Ireland from 25 October 1760 until 1 January 1801, and thereafter King of the United Kingdom of Great Britain and Ireland until his death. During George III's reign, Great Britain lost many of its colonies in North America; the rebellious colonies later formed the United States. Also during his reign, the realms of Great Britain and Ireland united to form the United Kingdom. George III suffered from a mental disease, now thought to be porphyria. After a final relapse in 1811, George's eldest son, The Prince George, Prince of Wales, reigned as Prince Regent. Upon George III's death, the Prince of Wales succeeded his father to become George IV.