George III

George III's reign saw the outbreak of the American Revolutionary War after colonial protests against British taxation. Britain lost the war after the French intervention. The Treaty of Paris in 1783 recognized American independence, ending British control of the Thirteen Colonies.

George III gave royal assent to the Acts of Union, which united Great Britain and Ireland into the United Kingdom of Great Britain and Ireland. This created a single parliament in London and ended the Irish Parliament. The union took effect on January 1, 1801.

George III's reign included the Napoleonic Wars against France under Napoleon Bonaparte. Britain fought coalitions across Europe and at sea. The wars ended with Napoleon's defeat at Waterloo in 1815, establishing British naval supremacy and colonial expansion.

George III suffered a final relapse of mental illness, likely due to porphyria. He became permanently incapacitated, leading to the Regency Act of 1811. His son George IV became Prince Regent, ruling in his stead until George III's death in 1820.

George III died at Windsor Castle at age 81, blind and deaf. He was buried in St George's Chapel. His 60-year reign was the longest of any British monarch at that time. His death ended the Regency era and passed the throne to George IV.