In short
On September 1, 1939, Nazi Germany launched a massive military assault on Poland, deploying 1.5 million troops across the border and into Polish airspace. The Soviet Union invaded from the east two weeks later. Within five weeks, Poland was defeated and partitioned between the two powers—an outcome that shattered the post-World War I order and marked the start of World War II.
How it unfolded.
The five-minute version
What actually happened.
The invasion of Poland, also known as the September Campaign, Polish Campaign, and Polish Defensive War of 1939, was a joint attack on the Republic of Poland by Nazi Germany, the Slovak Republic, and the Soviet Union, which marked the beginning of World War II. The German invasion was preceded by the Danzig crisis and began on 1 September 1939, one week after the signing of the Molotov–Ribbentrop Pact between Germany and the Soviet Union, and one day after the Supreme Soviet of the Soviet Union had approved the pact. The Soviets invaded Poland on 17 September. The campaign ended on 6 October with Germany and the Soviet Union dividing the whole of Poland under the terms of the German–Soviet Frontier Treaty.
As it was happening
18 voices, 371 days.
One beat at a time. Click any dot on the timeline to jump, press play for autoplay, or use the arrow keys to step.
Munich Agreement signed
Britain, France, Germany, and Italy agree to allow German annexation of Czechoslovak territory, emboldening Hitler's territorial ambitions.
Voices from this moment (1)
Munich Agreement signed
Sep 29
“Britain, France, Germany, and Italy agree to allow German…”
As it was happening
18 voices, 371 days.
Day 0 · September 29, 1938
Munich Agreement signed
Britain, France, Germany, and Italy agree to allow German annexation of Czechoslovak territory, emboldening Hitler's territorial ambitions.
“Britain, France, Germany, and Italy agree to allow German…”
- Munich Agreement signed, Sep 29
Day 167 · March 15, 1939
Germany occupies Czechoslovakia
Hitler violates the Munich Agreement by invading and occupying the remainder of Czechoslovakia, establishing a German protectorate.
“Hitler violates the Munich Agreement by invading and…”
- Germany occupies Czechoslovakia, Mar 15
Day 328 · August 23, 1939
Molotov-Ribbentrop Pact signed
Nazi Germany and the Soviet Union sign a non-aggression treaty that includes a secret protocol dividing Poland and Eastern Europe into German and Soviet spheres of influence.
“Nazi Germany and the Soviet Union sign a non-aggression…”
- Molotov-Ribbentrop Pact signed, Aug 23
Day 337 · September 1, 1939
Germany invades Poland
At 4:45 a.m., German forces cross the Polish border. The Luftwaffe bombs airfields and cities. Hitler orders the invasion codenamed Operation White; the German battleship Schleswig-Holstein fires on the Polish garrison at Westerplatte.
“German Army Invades Poland; Britain and France Pledge…”
- The Times, Sep 1
“Hitler's Army Attacks Poland; Chamberlain Warns of 'State…”
- The New York Times, Sep 1
“Deutsches Heer marschiert in Polen ein - Sicherung der…”
- Völkischer Beobachter, Sep 1
“L'Allemagne attaque la Pologne - La France mobilise”
- Le Petit Parisien, Sep 1
“I have resolved to speak to Poland only in the language…”
- Speech to the Reichstag, September 1, 1939, Sep 1
“We shall defend every inch of Polish soil.”
- Synthesized from period accounts - Polish military communiques, September 1939, Sep 1
“At 4:45 a.”
- Germany invades Poland, Sep 1
Day 339 · September 3, 1939
Britain and France declare war
Britain and France declare war on Germany, though they are unable to mount effective assistance to Poland.
“This country is at war with Germany.”
- Radio broadcast to the British nation, September 3, 1939, Sep 3
“War Declared: Britain's Ultimatum to Germany Expires”
- The Daily Telegraph, Sep 3
“The machine of Nazi conquest has been set in motion.”
- Synthesized from period accounts - American newspaper columns, September 1939, Sep 3
“Britain and France declare war on Germany, though they are…”
- Britain and France declare war, Sep 3
Day 342 · September 6, 1939
Poland launches counteroffensive
The Polish military, outnumbered and outequipped, attempts a series of counteroffensives including the Battle of the Bzura (September 19–October 5), the largest battle of the campaign.
“The Polish military, outnumbered and outequipped, attempts…”
- Poland launches counteroffensive, Sep 6
Day 353 · September 17, 1939
Soviet Union invades from the east
Soviet forces invade Poland from the east under the terms of the Molotov-Ribbentrop Pact, encircling Polish forces and sealing Poland's fate.
“DE: 'Die Sowjetunion konnte nicht indifferent bleiben…”
- Statement to the Supreme Soviet, September 17, 1939, Sep 17
“Soviet forces invade Poland from the east under the terms…”
- Soviet Union invades from the east, Sep 17
Day 371 · October 5, 1939
Poland surrenders
Polish forces are defeated. The last operational units cease fighting. Poland is partitioned between Germany and the Soviet Union; the Polish government flees to Romania and eventually Britain.
“Polish forces are defeated.”
- Poland surrenders, Oct 5
Front pages.
3 outlets carried the story: The Times, The New York Times, Völkischer Beobachter.
Media coverage
What the world was reading.
5 pieces, ranked by how much they shaped the discourse.
The Times
Newspaper · United Kingdom · Sep 1, 1939
"German Army Invades Poland; Britain and France Pledge Support"
Germany launched a full-scale military assault on Poland early this morning, with reports of heavy bombing in Warsaw and German mechanised units crossing the border at multiple points. British and French governments issued immediate statements of solidarity with the Polish nation.
- Sep 1, 1939
The New York Times
Newspaper · United States
"Hitler's Army Attacks Poland; Chamberlain Warns of 'State of War'"
In a dramatic escalation of European tensions, Nazi Germany's forces invaded Poland at dawn, with German air squadrons striking at Polish cities and airfields. Prime Minister Chamberlain declared that Britain would honour its obligations to Poland.
- Sep 1, 1939
Le Petit Parisien
Newspaper · France
"L'Allemagne attaque la Pologne - La France mobilise"
FR: 'L'Allemagne attaque la Pologne - La France mobilise' / EN: 'Germany Attacks Poland - France Mobilizes'. French newspapers reported the German invasion with urgent calls for national mobilization and reaffirmed France's commitment to the Polish alliance.
- Sep 3, 1939
The Daily Telegraph
Newspaper · United Kingdom
"War Declared: Britain's Ultimatum to Germany Expires"
As Britain's ultimatum to Nazi Germany expired at 11 a.m. this Sunday morning, Prime Minister Chamberlain formally declared a state of war. The invasion of Poland has triggered the machinery of alliance commitments and the onset of continental conflict.
- Sep 1, 1939
Völkischer Beobachter
Newspaper · Germany
"Deutsches Heer marschiert in Polen ein - Sicherung der Ostgrenze beginnt"
DE: 'Deutsches Heer marschiert in Polen ein - Sicherung der Ostgrenze beginnt' / EN: 'German Army Marches into Poland - Security of Eastern Border Begins'. Nazi state media portrayed the invasion as a defensive operation and assertion of German sovereignty over disputed territories.
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Sources & citations.
Sources
Where this came from.
Every claim on this page traces to a public, license-clean source. We don't asterisk well.
Wikipedia
1 source- 1.Germany invaded Poland
en.wikipedia.org