United Kingdom of Great Britain and Ireland

Sovereign state in Northwestern Europe (1801–1922) United Kingdom of Great Britain and Ireland1801–1922 FlagMotto: "Dieu et mon droit" (French) "God and my right"Anthem: "God Save the King/Queen" The United Kingdom of Great Britain and Ireland shown in green in 1914Show map of EuropeThe United Kingdom of Great Britain and Ireland with its colonies and dominions in 1921Capitaland largest cityLondon51°30′N 0°7′W / 51.500°N 0.117°W / 51.500; -0.117Official languagesEnglishDemonymsBritishBritonsGovernmentUnitary parliamentary constitutional monarchyMonarch • 1801–1820 George III (first)• 1910–1922 George V (last) Prime Minister • 1801 William Pitt the Younger (first)• 1922 Bonar Law (last) LegislatureParliament• Upper houseHouse of Lords• Lower houseHouse of CommonsHistory • Acts of Union 1 January 1801• Anglo-Irish Treaty 6 December 1921• Irish Free State Constitution Act 6 December 1922• Titles amended 16 April 1927 Population• 1911 census 45,221,000 Currency Pound sterling Irish pound (1801–26) Preceded by Succeeded by Kingdom of Great Britain Kingdom of Ireland United Kingdom of Great Britain and Northern Ireland Irish Free State Thi