United Kingdom

=== World wars and partition of Ireland ===
{{Main|History of the United Kingdom during the First World War|Partition of Ireland|Interwar Britain|United Kingdom home front during the Second World War|Military history of the United Kingdom during World War II}}
[[File:Wreaths Are Laid at the Cenotaph, London During Remembrance Sunday Service MOD 45152052.jpg|thumb|Wreaths being laid during the [[Remembrance Sunday]] service at the [[The Cenotaph|Cenotaph]] in Whitehall, London]]

Britain was one of the principal [[Allies of World War I|Allies]] that defeated the [[Central Powers]] in the [[First World War]] (1914–1918). Alongside their French, Russian and (after 1917) American counterparts,<ref>Turner, John (1988). ''Britain and the First World War''. London: Unwin Hyman. pp. 22–35. {{ISBN|978-0-04-445109-9}}.</ref> British armed forces were engaged across much of the British Empire and in several regions of Europe, particularly on the [[Western Front (World War I)|Western Front]].<ref name="Westwell&Cove" /> The high fatalities of [[trench warfare]] caused the loss of much of a generation of men, with lasting social effects in the nation and a great disruption in the social order. Britain had suffered 2.5&nbsp;million casualties and finished the war with a huge national debt.<ref name="Westwell&Cove">Westwell, I.; Cove, D. (eds) (2002). ''History of World War I, Volume 3''. London: Marshall Cavendish. pp. 698, 705. {{ISBN|978-0-7614-7231-5}}.</ref> The consequences of the war persuaded the government to expand the right to vote in national and local elections with the [[Representation of the People Act 1918]].<ref name="Westwell&Cove" /> After the war, Britain became a permanent member of the Executive Council of the [[League of Nations]] and received a [[League of Nations mandate|mandate]] over a number of former German and [[Ottoman Empire|Ottoman]] colonies. Under the leadership of [[David Lloyd George]], the British Empire reached its greatest extent, covering a fifth of the world's land surface and a quarter of its population.<ref>Turner, J. (1988). ''Britain and the First World War''. Abingdon: Routledge. p. 41. {{ISBN|978-0-04-445109-9}}.</ref>

By the mid-1920s, most of the British population could listen to [[BBC]] radio programmes.<ref>{{Cite web |date=15 June 2020 |title=100 years of radio since Marconi's big breakthrough |url=https://www.ofcom.org.uk/about-ofcom/latest/features-and-news/100-years-of-radio |access-date=17 November 2020 |website=Ofcom |archive-date=4 August 2020 |archive-url=https://web.archive.org/web/20200804031332/https://www.ofcom.org.uk/about-ofcom/latest/features-and-news/100-years-of-radio |url-status=live }}</ref><ref>{{Cite web |title=History of the BBC: The origins of BBC Local Radio |url=https://www.bbc.com/historyofthebbc/research/local-radio |access-date=18 September 2022 |website=bbc.com |last=Linfoot |first=Matthew |archive-date=20 September 2022 |archive-url=https://web.archive.org/web/20220920232207/https://www.bbc.com/historyofthebbc/research/local-radio/ |url-status=live }}</ref> Experimental television broadcasts [[History of television#United Kingdom|began in 1929]] and the [[First day of BBC television|first scheduled BBC Television Service]] commenced in 1936.<ref>{{Cite web |title=History of the BBC: 1920s |url=https://www.bbc.com/historyofthebbc/timelines/1920s |access-date=18 September 2022 |website=bbc.com |language=en |archive-date=26 September 2022 |archive-url=https://web.archive.org/web/20220926064808/https://www.bbc.com/historyofthebbc/timelines/1920s |url-status=live }}</ref> The rise of [[Irish nationalism]], and disputes within Ireland over the terms of [[Irish Home Rule]], led eventually to the [[Partition of Ireland|partition of the island]] in 1921.<ref>[[SR&O 1921]]/533 of 3 May 1921.</ref> The [[Irish Free State]] became independent, initially with [[Dominion]] status in 1922, and [[Statute of Westminster 1931#Irish Free State|unambiguously independent in 1931]]. Northern Ireland remained part of the United Kingdom.<ref>{{Cite web |title=The Anglo-Irish Treaty, 6&nbsp;December 1921 |url=http://cain.ulst.ac.uk/issues/politics/docs/ait1921.htm |access-date=15 May 2006 |website=CAIN Web Service |archive-date=14 May 2012 |archive-url=https://web.archive.org/web/20120514145108/http://cain.ulst.ac.uk/issues/politics/docs/ait1921.htm |url-status=live }}</ref> The [[1928 Equal Franchise Act]] gave women electoral equality with men in national elections. Strikes in the mid-1920s culminated in the [[General Strike of 1926]], which ended in a victory for the government led by [[Stanley Baldwin]]. Britain had still not recovered from the effects of the First World War when the [[Great Depression in the United Kingdom|Great Depression]] (1929–1932) led to considerable unemployment and hardship in the old industrial areas, as well as political and social unrest with rising membership in communist and socialist parties. A [[National Government (1931)|coalition government]] was formed in 1931.<ref>Rubinstein, W.D. (2004). ''Capitalism, Culture, and Decline in Britain, 1750–1990''. Abingdon: Routledge. p. 11. {{ISBN|978-0-415-03719-8}}.</ref>
[[File:Spitfire and Hurricane in the Battle of Britain Memorial Flight.jpg|thumb|[[Supermarine Spitfire|Spitfire]] and [[Hawker Hurricane|Hurricane]] as flown in the [[Battle of Britain]] during the [[Second World War]]]]

Nonetheless, "Britain was a very wealthy country, formidable in arms, ruthless in pursuit of its interests and sitting at the heart of a global production system."<ref name="Edgerton2012">{{Cite book|last=Edgerton|first=David|date=2012|title=Britain's War Machine|url=https://www.penguin.co.uk/books/55731/britain-s-war-machine/9780141026107.html|access-date=10 May 2020|publisher=www.penguin.co.uk|language=en|postscript=none|archive-date=28 April 2020|archive-url=https://web.archive.org/web/20200428080558/https://www.penguin.co.uk/books/55731/britain-s-war-machine/9780141026107.html|url-status=live}}; {{Cite web |title=Britain's War Machine: Weapons, Resources and Experts in the Second World War |url=https://reviews.history.ac.uk/review/1114 |access-date=10 May 2020 |website=Reviews in History |language=en |archive-date=12 June 2020 |archive-url=https://web.archive.org/web/20200612173058/https://reviews.history.ac.uk/review/1114 |url-status=live }}</ref> After [[Nazi Germany]] invaded Poland in 1939, Britain entered the [[Second World War]]. [[Winston Churchill]] became prime minister and head of a [[Churchill war ministry|coalition government]] in 1940. Despite the defeat of its European allies in the first year, Britain and its Empire continued the war against Germany. Churchill engaged industry, scientists and engineers to support the government and the military in the prosecution of the war effort.<ref name="Edgerton2012" />

In 1940, the [[Royal Air Force]] defeated the German [[Luftwaffe]] in the [[Battle of Britain]]. Urban areas suffered heavy bombing during [[the Blitz]]. The [[Grand Alliance (World War II)|Grand Alliance]] of Britain, the United States and the [[Soviet Union]] formed in 1941, leading the [[Allies of World War II|Allies]] against the [[Axis powers]]. There were eventual hard-fought victories in the [[Battle of the Atlantic]], the [[North Africa campaign]] and the [[Italian campaign (World War II)|Italian campaign]]. British forces played important roles in the [[Normandy landings]] of 1944 and the [[liberation of Europe]]. The British Army led the [[Burma campaign]] against Japan, and the [[British Pacific Fleet]] fought Japan at sea. British scientists [[British contribution to the Manhattan Project|contributed to the Manhattan Project]] whose task was to build an atomic weapon.<ref>{{cite book |author=Septimus H. Paul |url=https://books.google.com/books?id=fSZpgW-N628C&pg=PA1 |title=Nuclear Rivals: Anglo-American Atomic Relations, 1941–1952 |publisher=Ohio State U.P. |year=2000 |isbn=978-0-8142-0852-6 |pages=1–5}}</ref> Once built, it was decided, with British consent, to use the weapon against Japan.<ref>{{cite web |title=Minutes of a Meeting of the Combined Policy Committee, Washington, July 4, 1945 |url=https://history.state.gov/historicaldocuments/frus1945Berlinv01/d619 |url-status=live |archive-url=https://web.archive.org/web/20170918063918/https://history.state.gov/historicaldocuments/frus1945Berlinv01/d619 |archive-date=18 September 2017 |access-date=22 November 2017 |publisher=United States Department of State}}</ref> The wartime net losses in British national wealth amounted to 18.6% (£4.595 billion) of the prewar wealth (£24.68 billion), at 1938 prices.<ref>{{cite book|chapter=The United Kingdom: 'Victory at all costs'|first1=Stephen|last1=Broadberry|first2=Peter|last2=Howlett|title=The economics of World War II: Six great powers in international comparison|editor-last=Harrison|editor-first=Michael|publisher=Cambridge University Press|date=1998|page=69|url=http://ndl.ethernet.edu.et/bitstream/123456789/13137/1/300%20.%20Mark_Harrison.pdf|access-date=22 November 2023|archive-date=12 November 2023|archive-url=https://web.archive.org/web/20231112071259/http://ndl.ethernet.edu.et/bitstream/123456789/13137/1/300%20.%20Mark_Harrison.pdf|url-status=live}}</ref>