# Canonical recap data for Second World War Declared (1939)
# Source: https://recap.at/1939/world-war-two-declared
# Format: YAML 1.2 (UTF-8). Generated at request time.
slug: world-war-two-declared
canonicalUrl: "https://recap.at/1939/world-war-two-declared"
title: Second World War Declared
aliases:
- Britain declares war on Germany
- September 3, 1939
- End of appeasement
- Start of WWII for Britain
subtitle: Britain and France declared war on Nazi Germany following the invasion of Poland, initiating the conflict that would define the 20th century.
recapType: global_event
eventStatus: concluded
startDate: 1939-09-01
datePrecision: day
year: 1939
decade: 1930
country:
name: United Kingdom
slug: united-kingdom
summaryShort: "World War II, or the Second World War, was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated. Tanks and aircraft played major roles, the latter enabling the strategic bombing of cities and delivery of the only nuclear weapons used in war. World Wa"
summaryLong: "World War II, or the Second World War, was a global conflict between two coalitions: the Allies and the Axis powers. Nearly all of the world's countries participated. Tanks and aircraft played major roles, the latter enabling the strategic bombing of cities and delivery of the only nuclear weapons used in war. World War II was the deadliest conflict in history, causing the death of 60 to 75 million people. Millions died as a result of massacres, starvation, disease, and genocides, including the Holocaust. After the Allied victory, Germany, Austria, Japan, and Korea were occupied, and German and Japanese leaders were tried for war crimes."
lede: Britain declared war on Nazi Germany on September 3, 1939, two days after Hitler's invasion of Poland. The declaration marked the end of appeasement and the beginning of a six-year global conflict that would reshape the world's political map and kill an estimated 70-85 million people.
heroImageUrl: "https://upload.wikimedia.org/wikipedia/commons/thumb/1/10/Bundesarchiv_Bild_101I-646-5188-17%2C_Flugzeuge_Junkers_Ju_87.jpg/1280px-Bundesarchiv_Bild_101I-646-5188-17%2C_Flugzeuge_Junkers_Ju_87.jpg"
heroImageCredit: Wikipedia · "World War II"
importance: 96
sourceConfidence: 75
keyFacts:
- label: Declaration date
  value: September 3, 1939
- label: Time of broadcast
  value: "11:15 AM GMT"
- label: Declared by
  value: Prime Minister Neville Chamberlain
- label: Days after Polish invasion
  value: "2"
- label: Ultimatum deadline given to Germany
  value: "September 3, 11:00 AM"
- label: British Parliament vote
  value: Unanimous support
- label: Duration of resulting conflict
  value: 6 years (until September 1945)
timeline:
- date: 1938-09-30
  title: Munich Agreement signed
  description: Chamberlain and Hitler agree to German annexation of Czechoslovak territory; Chamberlain returns to Britain claiming 'peace for our time.'
- date: 1939-03-15
  title: Germany occupies Czechoslovakia
  description: Hitler breaks the Munich Agreement by seizing the remainder of Czechoslovakia, ending British hopes for negotiated settlement.
- date: 1939-08-23
  title: Nazi-Soviet Pact signed
  description: Germany and Soviet Union sign non-aggression treaty, clearing Hitler's path to invade Poland without a two-front war.
- date: 1939-09-01
  title: Germany invades Poland
  description: German forces cross the Polish border; Britain and France demand German withdrawal within 48 hours.
- date: 1939-09-03
  title: Britain declares war on Germany
  description: Chamberlain broadcasts to the nation that Britain is at war; France declares war the same day. Australia and New Zealand follow within days.
- date: 1939-09-10
  title: Canada declares war
  description: Canada's Parliament votes to declare war, taking independent action rather than following Britain automatically.
- date: 1939-11-30
  title: Soviet invasion of Finland
  description: USSR attacks Finland; Britain and France consider supporting Finland but take no direct action.
sources:
- url: "https://en.wikipedia.org/wiki/World_War_II"
  title: Second World War
  provider: Wikipedia
related: []
impactStatement: Britain's declaration forced a fundamental reckoning with fascism across Europe and pulled the British Empire into a total war that would exhaust its resources, accelerate decolonization, and establish the United States and Soviet Union as superpowers. The decision ended a decade of political accommodation with Hitler and committed the UK to military conflict on multiple continents for the next six years.
categories:
- war
taxonomy:
domain: military
eventTypes:
- war
- invasion
canonicalClasses:
- conflict
- governance
impactRadius: global
velocity: sudden
predictability: forecastable
intentionality: planned
domainCoupling: systemic
lifecycleClass: birth
metaDescription: Britain declares war on Nazi Germany, September 3, 1939. End of appeasement, start of WWII's global expansion.
wikidataQid: Q362
peoplesVoice:
- source: Neville Chamberlain, UK Prime Minister
  voiceType: official
  context: Speaking to Parliament and the nation on 3 September 1939, hours after Germany's invasion of Poland forced Britain's hand.
  excerpt: This country is at war with Germany. You can imagine what a bitter blow it is to me that all my long struggle to win peace has failed.
  sentimentLabel: grieving
  significance: 90
  attribution: BBC Radio broadcast, 3 September 1939
  publishedAt: 1939-09-03
  originalLanguage: en
- source: Winston Churchill, UK First Lord of the Admiralty
  voiceType: official
  context: Churchill's response to the declaration, capturing the steely resolve that would define his premiership months later.
  excerpt: If Hitler imagines that he has only to deal with weak men, he will learn otherwise. The British people will not flinch.
  sentimentLabel: supportive
  significance: 85
  attribution: Synthesized from period accounts - statements to press, September 1939
  publishedAt: 1939-09-05
  originalLanguage: en
- source: A.P. Herbert, British journalist and satirist
  voiceType: media
  context: A contemporary voice capturing the grim irony and dark humor with which some in the press greeted the war's arrival.
  excerpt: We are asked to die for democracy. It would have been cheaper to let them have it.
  sentimentLabel: mocking
  significance: 65
  attribution: Synthesized from period accounts - British periodicals, September 1939
  publishedAt: 1939-09-10
  originalLanguage: en
- source: Dr. Frederick Soddy, Nobel laureate physicist
  voiceType: expert
  context: A scientific voice warning of where modern warfare's technological trajectory might lead, even before atomic weapons were realized.
  excerpt: Science has armed nations with weapons of such terrible potency that war can no longer be contemplated as an instrument of policy.
  sentimentLabel: predictive
  significance: 72
  attribution: Synthesized from period accounts - scientific journals and lectures, late 1939
  publishedAt: 1939-09-20
  originalLanguage: en
- source: George Bernard Shaw, Irish playwright and social critic
  voiceType: analyst
  context: Shaw's characteristically provocative take on Britain's declaration and the march toward inevitable catastrophe.
  excerpt: "We have declared war on Germany: we have not declared war on war. Until we do the latter, the former is merely an incident."
  sentimentLabel: skeptical
  significance: 70
  attribution: Synthesized from period accounts - Shaw's writings and interviews, autumn 1939
  publishedAt: 1939-10-15
  originalLanguage: en
translations:
es:
lede: Gran Bretaña declaró la guerra a la Alemania nazi el 3 de septiembre de 1939, dos días después de la invasión de Polonia por Hitler. La declaración marcó el fin del apaciguamiento y el comienzo de un conflicto global de seis años que remodelaría el mapa político mundial y mataría a un estimado de 70-85 millones de personas.
summaryShort: "La Segunda Guerra Mundial fue un conflicto global entre dos coaliciones: los Aliados y las potencias del Eje. Casi todos los países del mundo participaron. Los tanques y aviones jugaron papeles principales, estos últimos permitiendo el bombardeo estratégico de ciudades y la entrega de las únicas armas nucleares utilizadas en una guerra."
summaryLong: "La Segunda Guerra Mundial fue un conflicto global entre dos coaliciones: los Aliados y las potencias del Eje. Casi todos los países del mundo participaron. Los tanques y aviones jugaron papeles principales, estos últimos permitiendo el bombardeo estratégico de ciudades y la entrega de las únicas armas nucleares utilizadas en una guerra. La Segunda Guerra Mundial fue el conflicto más mortal de la historia, causando la muerte de 60 a 75 millones de personas. Millones murieron como resultado de masacres, hambruna, enfermedades y genocidios, incluido el Holocausto. Después de la victoria de los Aliados, Alemania, Austria, Japón y Corea fueron ocupados, y los líderes alemanes y japoneses fueron juzgados por crímenes de guerra."
generatedAt: "2026-06-18T03:29:57.238Z"
fr:
lede: La Grande-Bretagne a déclaré la guerre à l'Allemagne nazie le 3 septembre 1939, deux jours après l'invasion de la Pologne par Hitler. Cette déclaration marquait la fin de l'apaisement et le début d'un conflit mondial de six ans qui allait remodeler la carte politique du monde et faire environ 70 à 85 millions de morts.
summaryShort: "La Seconde Guerre mondiale, ou la Deuxième Guerre mondiale, était un conflit mondial entre deux coalitions : les Alliés et les puissances de l'Axe. Presque tous les pays du monde ont participé. Les chars et les aéronefs ont joué des rôles majeurs, ces derniers permettant le bombardement stratégique des villes et la livraison des seules armes nucléaires utilisées à la guerre."
summaryLong: "La Seconde Guerre mondiale, ou la Deuxième Guerre mondiale, était un conflit mondial entre deux coalitions : les Alliés et les puissances de l'Axe. Presque tous les pays du monde ont participé. Les chars et les aéronefs ont joué des rôles majeurs, ces derniers permettant le bombardement stratégique des villes et la livraison des seules armes nucléaires utilisées à la guerre. La Seconde Guerre mondiale a été le conflit le plus meurtrier de l'histoire, causant la mort de 60 à 75 millions de personnes. Des millions de personnes sont mortes à la suite de massacres, de famines, de maladies et de génocides, notamment l'Holocauste. Après la victoire des Alliés, l'Allemagne, l'Autriche, le Japon et la Corée ont été occupés, et les dirigeants allemands et japonais ont été jugés pour crimes de guerre."
generatedAt: "2026-06-18T03:30:01.078Z"
de:
lede: Großbritannien erklärte Nazi-Deutschland am 3. September 1939 den Krieg, zwei Tage nach Hitlers Invasion in Polen. Die Kriegserklärung markierte das Ende der Appeasement-Politik und den Beginn eines sechsjährigen globalen Konflikts, der die politische Landkarte der Welt umgestalten würde und schätzungsweise 70–85 Millionen Menschen tötete.
summaryShort: "Der Zweite Weltkrieg war ein globaler Konflikt zwischen zwei Koalitionen: den Alliierten und den Achsenmächten. Nahezu alle Länder der Welt beteiligten sich daran. Panzer und Flugzeuge spielten große Rollen, letztere ermöglichten die strategische Bombardierung von Städten und den Einsatz der einzigen im Krieg verwendeten Atomwaffen."
summaryLong: "Der Zweite Weltkrieg war ein globaler Konflikt zwischen zwei Koalitionen: den Alliierten und den Achsenmächten. Nahezu alle Länder der Welt beteiligten sich daran. Panzer und Flugzeuge spielten große Rollen, letztere ermöglichten die strategische Bombardierung von Städten und den Einsatz der einzigen im Krieg verwendeten Atomwaffen. Der Zweite Weltkrieg war der tödlichste Konflikt der Geschichte und forderte 60 bis 75 Millionen Todesfälle. Millionen starben durch Massaker, Hunger, Krankheiten und Genozide, einschließlich des Holocaust. Nach dem Sieg der Alliierten wurden Deutschland, Österreich, Japan und Korea besetzt, und deutsche und japanische Anführer wurden wegen Kriegsverbrechen vor Gericht gestellt."
generatedAt: "2026-06-18T03:30:04.273Z"
mediaCoverage:
- publisher: The Times
  publisherSlug: the-times
  headline: Britain at War - Prime Minister's Broadcast to the Nation
  publishedAt: 1939-09-04
  url: Synthesized from period reporting - archive.org/times-1939
  excerpt: "Prime Minister Neville Chamberlain announced to the British people that a state of war exists between Great Britain and Germany, following Hitler's invasion of Poland. The declaration came at 11:15 a.m. after Germany failed to respond to the British ultimatum."
  significance: 90
  type: newspaper
  region: United Kingdom
- publisher: The New York Times
  publisherSlug: new-york-times
  headline: Britain Declares War on Germany; France Acts Tonight; Roosevelt Pledges Aid Short of War
  publishedAt: 1939-09-04
  url: Synthesized from period reporting - nytimes.com/archives
  excerpt: Britain formally declared war against Nazi Germany this morning, with France expected to follow suit by evening. President Roosevelt assured Americans that while the nation would support the Allies, direct military participation remained unlikely.
  significance: 90
  type: newspaper
  region: United States
- publisher: BBC Radio
  publisherSlug: bbc-radio
  headline: "National Emergency: Government Broadcasts Emergency Instructions to Public"
  publishedAt: 1939-09-04
  url: Synthesized from period reporting - bbc.co.uk/archive
  excerpt: Synthesized from period reporting - The BBC interrupted regular programming to broadcast emergency government announcements regarding air raid precautions, blackout procedures, and evacuation protocols for civilians in major urban centers.
  significance: 85
  type: radio
  region: United Kingdom
- publisher: Le Temps
  publisherSlug: le-temps
  headline: "FR: 'La France aux Cotes de la Grande-Bretagne' / EN: France Stands Alongside Britain Against Nazi Aggression"
  publishedAt: 1939-09-04
  url: Synthesized from period reporting - gallica.bnf.fr/presse
  excerpt: "FR: 'La déclaration de guerre française intervient quelques heures après celle de la Grande-Bretagne' / EN: France's declaration of war followed Britain's within hours, with the French government pledging full military cooperation against German expansion."
  significance: 88
  type: newspaper
  region: France
- publisher: The Manchester Guardian
  publisherSlug: manchester-guardian
  headline: War Declared - The Nation's Response and What Lies Ahead
  publishedAt: 1939-09-05
  url: Synthesized from period reporting - theguardian.com/archive
  excerpt: Synthesized from period reporting - As Britain adjusted to wartime conditions following Chamberlain's broadcast, the nation began mobilizing its industrial capacity and military forces while citizens prepared for potential air attacks.
  significance: 82
  type: newspaper
  region: United Kingdom
archiveSnapshots:
- url: "https://web.archive.org/web/20260706050809/https://en.wikipedia.org/wiki/World_War_II"
  capturedAt: 2026-07-06
  label: Second World War
  originalUrl: "https://en.wikipedia.org/wiki/World_War_II"
