King George III of Great Britain: Reign Dates and Historical Significance

Reign: 1760–1820 (59 Years, 96 Days)

George III (George William Frederick; 4 June 1738 – 29 January 1820) reigned as King of Great Britain and Ireland from 25 October 1760 until his death on 29 January 1820. After the Acts of Union 1800, he became King of the United Kingdom of Great Britain and Ireland (1801–1820). He was also Elector (later King) of Hanover.

Key Milestones

• 1760: Accession at 22; first Hanoverian monarch born in Britain, English as first language.
• 1763: Treaty of Paris — Britain gains Canada, Florida; global empire peaks.
• 1775–1783: American Revolutionary War — loss of 13 colonies.
• 1788–89: First major mental health crisis (now believed porphyria or bipolar); Regency crisis.
• 1793–1815: French Revolutionary & Napoleonic Wars — Britain leads coalitions; Trafalgar (1805), Waterloo (1815).
• 1801: Act of Union with Ireland; Catholic Emancipation blocked by George.
• 1811–1820: Regency — Prince of Wales (future George IV) rules as Prince Regent after George deemed permanently incapacitated.
• 1820: Death at Windsor Castle, aged 81; longest-reigning British king (surpassed by Victoria 1896, Elizabeth II 2015).

Legacy: "The King Who Lost America" vs. "Farmer George"

• American view: Tyrant (Declaration of Independence grievances).
• British view: Model constitutional monarch; patron of science (Royal Society), agriculture (Kew Gardens), arts (Royal Academy); "Farmer George" for simple tastes.
• Medical: Case transformed psychiatry; moved from "madness" to treatable illness.
• Constitutional: Last monarch to actively direct policy; after him, cabinet responsibility to Parliament solidified.

Family

Married Charlotte of Mecklenburg-Strelitz (1761); 15 children (13 survived). Grandfather of Queen Victoria; ancestor of all current European monarchs.