George III (1738-1820) succeeded his grandfather, George II, in 1760. During the following 60 years, several revolutions modified every aspect of British life. The French Revolution threatened Britain's stability. The American Revolution cost Britain its American colonies. The Industrial Revolution radically changed society and more than doubled the British population during the reign of George III. New territories were acquired in place of those in America, however. The Act of Union, which became effective in 1801, brought Ireland into the kingdom. The kingdom then became known as the United Kingdom of Great Britain and Ireland.
George III took a far greater part in governing England than George I or George II. Hardworking and proud of being English, he tried to destroy the power of the Whig aristocrats, who had held control for many years under Walpole, Pelham, and the elder Pitt. George chose his ministers, especially Lord North and the younger William Pitt, with this in mind (see NORTH, LORD). But George III suffered from a disease now called porphyria, a mental disorder that sometimes has delirium as a symptom. Porphyria is not a mental illness, though those around George III treated him as if he were insane. His wife was Charlotte of Mecklenburg-Strelitz.