World War II · Europe · 1939
The Invasion of Poland1 September – 6 October 1939: an atlas, nine chapters and the record
Before dawn on 1 September 1939 German dive bombers struck the Vistula bridges at Tczew and the town of Wieluń, and at 04:45 an old battleship opened fire on the Polish depot at Westerplatte in Danzig. Sixteen days later the Red Army invaded from the east. Poland fought for thirty-six days, and its government never surrendered. This collection follows the campaign from the Corridor and the Enigma breakers to Kock and Katyn.
✦ Tap to fire the flak · watch the clock
The battleship Schleswig-Holstein in the Danzig harbor canal during the shelling of Westerplatte, September 1939. Instytut Pamięci Narodowej (IPN); public domain, via Wikimedia Commons. Photographs toned for this page; the dawn sky, smoke, gunfire, aircraft and flak are illustrations.
Start here · Why it matters
The first campaign of the Second World War, fought alone against two invaders.
At about 04:34 on 1 September 1939 German dive bombers attacked the Polish positions at the Vistula bridges at Tczew. Minutes later Stukas bombed Wieluń, and at 04:45 the battleship Schleswig-Holstein opened fire on the Polish Military Transit Depot at Westerplatte. Germany, with Slovakia beside it, attacked from Pomerania, East Prussia, Silesia, Moravia and Slovakia under the plan called Case White. On 17 September the Red Army crossed the eastern frontier under the secret protocol of the Molotov–Ribbentrop pact. Warsaw capitulated on 28 September, Hel on 2 October, and the last Polish field force surrendered at Kock on 6 October.
Britain and France declared war on 3 September, but no help came in time; the French advance into the Saar stopped on 12 September. Poland fought on for five weeks, not the few days of popular memory. Its air force was not destroyed on the ground, its cavalry did not charge tanks, and its government never surrendered: it crossed into Romania and was re-formed in Paris on 30 September. The Polish codebreakers had already handed the Enigma secret to Britain and France at Pyry in July 1939.
Germany and the Soviet Union divided the country along a line fixed on 28 September and set out to destroy its leaders, from Piaśnica and Palmiry to Katyn. Start with the atlas below, follow the day-by-day timeline, or read the nine chapters in order. Every number on this page comes with its range and its source.
All figures are estimates and vary with what is counted; the ranges and their sources are set out in the numbers section and in each chapter.
Interactive atlas
Follow the campaign from the Baltic to the Romanian border.
Four maps in one: Europe from London to Moscow; Poland in its 1939 borders, with the line of the secret protocol of 23 August and the final German–Soviet line of 28 September; the Gulf of Danzig, with Westerplatte, the Post Office, Gdynia, Oksywie and Hel; and Warsaw with Modlin, the Kampinos Forest and the lower Bzura. Step through eight phases from Versailles to the occupation, or play the campaign, and the places, armies and arrows change with them. Every record cites its source and links to the chapter that tells its story.
Positions, fronts and arrows are approximate and schematic, after Zaloga (2002), Kochanski (2012), Moorhouse (2019), the Polish official history (Polskie Siły Zbrojne w II Wojnie Światowej, vol. 1) and the chapters of this collection. Coastlines: Natural Earth via world-atlas. Markers for memorials show places as they are today.
Timeline
From Versailles to the last surrender, and after.
Seventy years in 55 entries, densest for the five weeks from the pact of 23 August to the surrender at Kock on 6 October 1939. Times are local; where the sources disagree, both times are given. Each entry links to the chapter that tells it in full.
1918 – July 1939: the road to war
- Independence Piłsudski takes command of the Polish armed forces; Poland marks its Independence Day. Chapter 1 →
- Versailles The peace treaty gives Poland the Corridor to the Baltic and makes Danzig a Free City under the League of Nations. Chapter 1 →
- The Battle of Warsaw The Red Army is driven back from Warsaw. American volunteers of the Kościuszko Squadron fly for Poland. Chapter 4 →
- Enigma broken Marian Rejewski reconstructs the wiring of the German military Enigma machine. Chapter 1 →
- A declaration with Germany Germany and Poland sign a declaration of nonaggression. Chapter 1 →
- The demand Ribbentrop asks Ambassador Józef Lipski for Danzig and an extraterritorial road across the Corridor. Chapter 1 →
- The British guarantee Chamberlain announces Britain’s guarantee of Poland’s independence. Chapter 1 →
- Case White Hitler’s directive orders the Wehrmacht to be ready to attack Poland from 1 September. Chapter 1 →
- Beck answers Hitler Foreign Minister Józef Beck rejects the German demands in a speech to the Sejm. Chapter 1 →
- Pyry In the Kabaty Woods outside Warsaw the Cipher Bureau reveals its Enigma solution to British and French codebreakers. Chapter 1 →
August 1939: the last weeks of peace
- The Molotov–Ribbentrop pact The German–Soviet nonaggression pact is signed in Moscow; its secret protocol divides Poland along the Narew, Vistula and San. Chapter 1 →
- An alliance and a postponement The Anglo-Polish Agreement of Mutual Assistance is signed in London, and Hitler postpones the attack planned for 26 August. Schleswig-Holstein arrives in Danzig. Chapter 1 →
- Mobilization Polish general mobilization is ordered, suspended at British and French request, and reissued for 31 August. Chapter 1 →
- Operation Peking The destroyers Błyskawica, Burza and Grom sail for Britain; they tie up at Leith on 1 September. Chapter 7 →
- Gleiwitz Hitler signs Directive No. 1. At about 20:00 SS men stage a fake Polish attack on the German radio station at Gleiwitz. Chapter 1 →
1 September 1939: the first day
- Tczew Ju 87s attack the approaches to the Vistula bridges; Polish engineers blow the bridges that morning. Chapter 2 →
- Wieluń Stukas bomb the market town, the All Saints Hospital among the first buildings hit. The IPN identified 127 dead; estimates run to about 1,200 or more. Chapter 3 →
- Westerplatte and the Post Office Schleswig-Holstein opens fire on Westerplatte and the attack on the Polish Post Office in Danzig begins. German armies cross the frontier between about 04:45 and 05:00. Chapter 2 →
- The first air victories Near Kraków Capt. Mieczysław Medwecki is shot down; minutes later two Do 17s attacked by 2nd Lt. Władysław Gnyś crash at Żurada. Chapter 4 →
- Over Warsaw The Pursuit Brigade meets the first raid on the capital near Nieporęt; two more raids follow. Chapter 4 →
- Mokra and Mława The Volhynian Cavalry Brigade holds the 4th Panzer Division at Mokra; the 20th Infantry Division repulses Panzer Division Kempf at Mława. Roosevelt appeals against the bombing of civilians. Chapter 3 →
- The Post Office falls After 13 to 15 hours the defenders surrender; 38 of them are executed on 5 October. Chapter 2 →
- Krojanty The 18th Pomeranian Uhlans charge a German infantry battalion; Col. Kazimierz Mastalerz is killed. Chapter 3 →
2 – 16 September: the frontier, the Vistula and the Narew
- Westerplatte bombed A dive-bomber raid collapses Guardhouse No. 5 and destroys the radio and kitchen. Chapter 2 →
- Britain and France declare war Britain at 11:00, France at 17:00. Shooting and killings in Bydgoszcz; the Tuchola Forest pocket closes; Wicher and Gryf are sunk at Hel. Chapter 3 →
- Piotrków and Kraków The 1st Panzer Division takes Piotrków; Kraków is abandoned, and Rydz-Śmigły orders the army behind the Vistula, Narew and San. Chapter 3 →
- Westerplatte surrenders After seven days the garrison marches out. The high command leaves Warsaw for Brześć. Chapter 2 →
- Wizna Capt. Władysław Raginis’s garrison holds the Narew crossings against Guderian’s leading units until about midday on 10 September. Chapter 5 →
- Ochota and Wola The 4th Panzer Division attacks Warsaw and is thrown back. Stefan Starzyński becomes civil commissar of the defense. Chapter 6 →
- The Bzura Gen. Tadeusz Kutrzeba’s armies attack south across the Bzura, opening the largest battle of the campaign. Chapter 6 →
- Lwów besieged Advance units of the German 1st Mountain Division reach the outskirts of Lwów. Chapter 8 →
- Gdynia and Tallinn German troops enter Gdynia; the submarine Orzeł puts into Tallinn and is interned the next day. Chapter 7 →
- Brest Gen. Konstanty Plisowski holds the citadel; the garrison withdraws on the night of 16–17 September. Chapter 5 →
17 September – 6 October: two invaders and the last battles
- The Soviet invasion The Red Army crosses the eastern frontier between about 03:00 and 06:00. In Warsaw the Royal Castle is set on fire at 11:15. Chapter 8 →
- Into Romania The president, the government and the commander in chief cross the border at Kuty and are interned. Chapter 8 →
- The Orzeł escapes The crew breaks out of internment in Tallinn; the boat reaches Rosyth on 14 October without charts. Chapter 7 →
- The Bzura pocket destroyed About 30,000 men break through to Warsaw and Modlin; Gen. Bortnowski is captured. Chapter 6 →
- Oksywie and Wilno Kępa Oksywska falls and Col. Stanisław Dąbek dies at Babie Doły; Wilno falls to the Red Army. Chapter 7 →
- Grodno Soldiers, police, students and Scouts defend Grodno against the Soviet 15th Tank Corps. Chapter 8 →
- Lwów and Brest Lwów surrenders to the Red Army; German and Soviet commanders hand over Brest-Litovsk. Chapter 5 →
- Black Monday The heaviest air and artillery bombardment of the siege of Warsaw. Chapter 6 →
- Warsaw capitulates Kutrzeba and Blaskowitz sign the capitulation at 13:15. In Moscow the German–Soviet Boundary and Friendship Treaty is signed; the KOP wins at Szack. Chapter 6 →
- Modlin The fortress surrenders. Chapter 6 →
- A government in exile Władysław Raczkiewicz is sworn in as president in Paris; Gen. Władysław Sikorski becomes prime minister. Chapter 9 →
- Wytyczno and Hel The Border Protection Corps fights its last battle at Wytyczno. Hel’s capitulation is signed at Sopot, and German troops enter on 2 October. Chapter 7 →
- Kock Gen. Franciszek Kleeberg’s Polesie group fights the German XIV Motorized Corps and surrenders on 6 October, the end of the campaign. Chapter 8 →
1939 – 1990: occupation, exile and memory
- Sonderaktion Krakau 183 to 184 academics of Kraków are arrested. Chapter 9 →
- Piaśnica An estimated 12,000 to 14,000 people are killed in the forest near Wejherowo, most of them Poles from Pomerania. Chapter 9 →
- Palmiry Executions begin in the Kampinos Forest; more than 1,700 people are shot there by July 1941. Chapter 9 →
- Hubal Maj. Henryk Dobrzański, who fought on in uniform for seven months, is killed near Anielin. Chapter 8 →
- Katyn The NKVD shoots about 22,000 Polish officers, police and others taken prisoner in 1939, at Katyn, Kharkiv and Kalinin. Chapter 9 →
- No. 303 Squadron The Polish Kościuszko squadron is declared operational in the Battle of Britain. Chapter 9 →
- Karski at the White House Jan Karski, courier of the Polish Underground State, reports to President Roosevelt. Chapter 9 →
- Katyn admitted The Soviet Union admits NKVD responsibility for the Katyn massacre. Chapter 9 →
- The account closed The last president in exile hands his insignia to the elected president in Warsaw. Chapter 9 →
Sources: the timelines of the nine chapters, after Zaloga (2002), Moorhouse (2019), Kochanski (2012), Cynk (1998), the Museum of the Second World War in Gdańsk, the IPN and the other works cited in each chapter.
Nine chapters
Read the campaign in order.
Each chapter is a full article of 10,000 to 12,000 words, with interactive maps, a timeline, charts and tables of the numbers with their variants, cards for the people and units who stood out, archival photographs and sources cited in the text. Start with the Corridor and the codebreakers, or open any chapter; each links to the next.
Chapter 1 · 1918 – 1 Sep 1939
The Road to September: Danzig, the Corridor, the Pact and the Enigma Breakers
How Poland reached 1 September 1939: Versailles, Danzig and the Corridor, the German demands, the British guarantee, the Molotov-Ribbentrop pact and its secret protocol, the staged Gleiwitz attack, and the Polish mathematicians who broke Enigma and gave the secret to Britain and France.
Read chapter 1 →
Chapter 2 · 1 – 7 Sep 1939
Westerplatte and the Polish Post Office: The First Shots in Danzig
At dawn on 1 September 1939 the battleship Schleswig-Holstein fired on the Polish depot at Westerplatte, which held out for seven days, while postal workers defended the Polish Post Office in Danzig for most of a day. Thirty-eight of them were later executed.
Read chapter 2 →
Chapter 3 · 1 – 10 Sep 1939
The Frontier Battles: Wieluń, Mokra, Mława, Krojanty and the Corridor
In six days, 1–6 September 1939, German armies broke Poland’s forward defenses: the bombing of Wieluń, the stands at Mokra, Mława and Węgierska Górka, the Krojanty charge and its myth, the Corridor, Bydgoszcz and the retreat to the Vistula.
Read chapter 3 →
Chapter 4 · 1919 – 1940
The Air War: The Pursuit Brigade, the Bomber Brigade and the Kościuszko Squadron
The Polish Air Force was not destroyed on the ground on 1 September 1939. This chapter follows the Pursuit Brigade over Warsaw, the Bomber Brigade against the panzers, Władysław Gnyś’s first Allied air victories and the 111th Kościuszko Escadrille, founded by American volunteers.
Read chapter 4 →
Chapter 5 · 2 – 22 Sep 1939
Wizna, Brest and the Narew: Holding the Northern Front
The northern front, 4-22 September 1939: how a few hundred men under Capt. Władysław Raginis held the Wizna crossings against Guderian’s corps, how Gen. Konstanty Plisowski defended the Brest citadel, and what really happened at the German-Soviet ceremony in Brest.
Read chapter 5 →
Chapter 6 · 3 Sep – 1 Oct 1939
The Bzura and the Siege of Warsaw
From 8 to 29 September 1939: the government leaves Warsaw, the 4th Panzer Division is stopped at Ochota, Kutrzeba strikes on the Bzura in the largest battle of the campaign, and a besieged capital, filmed by American Julien Bryan, holds out until 28 September.
Read chapter 6 →
Chapter 7 · 26 Aug – 14 Oct 1939
The Coast and the Navy: Gdynia, Oksywie, Hel and the Escape of the Orzeł
How Poland’s small navy and its coast fought in September 1939: Operation Peking, the sinking of Wicher and Gryf at Hel, Col. Dąbek’s stand at Gdynia and Oksywie, the 32-day defense of Hel, and the Orzeł’s escape from Tallinn to Scotland without charts.
Read chapter 7 →
Chapter 8 · 12 Sep – 6 Oct 1939
17 September: The Soviet Invasion and the Last Battles
On 17 September 1939 the Red Army invaded eastern Poland. The government crossed into Romania, Lwów and Grodno fell, the Border Protection Corps fought at Szack and Wytyczno, and Gen. Kleeberg’s last battle at Kock ended the campaign on 6 October.
Read chapter 8 →
Chapter 9 · 1939 – today
Occupation, Exile and Memory
After the fighting ended, Germany and the Soviet Union partitioned Poland and set out to destroy its leaders, from Piaśnica and Palmiry to Katyn, while Polish soldiers, airmen, sailors and codebreakers fought on in exile. The cost of September, No. 303 Squadron, Jan Karski and how the campaign is remembered.
Read chapter 9 →Featured photographs, via Wikimedia Commons: the Kremlin, 23 August 1939, Mikhail Kalashnikov (public domain); Schleswig-Holstein, IPN (public domain); Wieluń, from C. Madajczyk (1970) (public domain); PZL.37 Łoś crews, 1939 (public domain); Brest-Litovsk, 22 September 1939, German propaganda photograph by Gutjahr, Nationaal Archief (CC0); Castle Square, D. Kobielski (1969) (public domain); ORP Błyskawica, Witold Pikiel, NAC (public domain); Białystok, 22 September 1939 (public domain); Westerplatte monument, Andrzej Otrębski (CC BY-SA 4.0).
Heroes and special units
The people and units who stood out in September.
Codebreakers and postal clerks, cavalry colonels and fighter pilots, a mayor, an American filmmaker and the crew of a submarine that escaped without charts. Each card summarizes a fuller portrait in its chapter. Where no free photograph exists, the card shows an insignia drawn for this collection in the period style, labeled as an illustration; these are not official emblems.
The Enigma breakers
Read chapter 1 →
Hero of September
Marian Rejewski
Mathematician, Cipher Bureau (1905–1980)
In December 1932 he reconstructed the wiring of the military Enigma, then designed the cyclometer and the bomba. He escaped through Romania and France and reached Britain in 1943, where he served in a Polish signals unit, not at Bletchley Park.
Chapter 1 →
Hero of September
Jerzy Różycki
Mathematician, Cipher Bureau (1909–1942)
Inventor of the “clock” method, which used the uneven frequencies of German letters to identify the fast right-hand wheel of the Enigma. He escaped with the Bureau in 1939, worked on in France, and died at sea on 9 January 1942.
Chapter 1 →
Hero of September
Henryk Zygalski
Mathematician, Cipher Bureau (1908–1978)
After the Germans changed their indicator procedure on 15 September 1938 he devised the perforated sheets that bear his name. Sheets made at Bletchley Park produced the first Allied solutions of wartime Enigma keys in 1939–40.
Chapter 1 →
IllustrationSpecial unit
The Cipher Bureau
Biuro Szyfrów, Polish General Staff
Formed in 1931 under Lt. Col. Gwido Langer, it read German Enigma traffic from 1932. At Pyry on 25–26 July 1939 it gave Britain and France its methods, the bomba design, the perforated sheets and two replica machines.
Chapter 1 →Photographs, via Wikimedia Commons: Rejewski, Różycki and Zygalski: portrait photographs, public domain; Zygalski sheets at Bletchley Park, Toby Oxborrow, CC BY-SA 2.0.
The first shots in Danzig
Read chapter 2 →
Hero of September
Henryk Sucharski
Major, commander of the Westerplatte depot
He took command on 3 December 1938 and pushed through the fortifications that let the garrison hold for seven days. His conduct during the battle is still debated; he signed the surrender on 7 September and died in Naples in 1946.
Chapter 2 →
Hero of September
Franciszek Dąbrowski
Captain, deputy commander at Westerplatte
He commanded the defense in the field and argued at the officers’ councils of 5 and 6 September for fighting on. In the account that emerged in the 1990s, he took effective command after the dive-bomber raid of 2 September.
Chapter 2 →
Hero of September
Konrad Guderski
Reserve second lieutenant of engineers, the Polish Post Office
Sent to Danzig by military intelligence in April 1939 to prepare the Post Office for defense, he led its staff against the first assaults on 1 September and was killed by the blast of his own grenade while stopping a breakthrough.
Chapter 2 →
IllustrationSpecial unit
The Westerplatte garrison
Wojskowa Składnica Tranzytowa
A treaty limit of 88 men, quietly built up to at least 208 soldiers and civilian staff. With one field gun, two anti-tank guns, four mortars and about 40 machine guns they held out from 1 to 7 September; about 15 were killed.
Chapter 2 →
IllustrationSpecial unit
The Post Office defenders
Polish Post Office No. 1, Danzig
About 56 to 58 postal workers and reservists, asked to hold for six hours, held for 13 to 15 until gasoline was set alight in the basement. Fourteen died; 38 were executed by the Germans on 5 October 1939.
Chapter 2 →Photographs, via Wikimedia Commons: Sucharski, from Historia Polski; Dąbrowski with the Westerplatte officers after the surrender, 7 September 1939; Guderski; Westerplatte burning, NAC 2-65; Post Office defenders, from Sz. Datner; all public domain.
The frontier battles
Read chapter 3 →Hero of September
Kazimierz Mastalerz
Colonel, commander, 18th Pomeranian Uhlans
He led the charge at Krojanty on the evening of 1 September, in which two squadrons scattered a German infantry battalion. When armored cars opened fire he rode forward to help a squadron commander and was killed beside him.
Chapter 3 →Hero of September
Tadeusz Semik
Captain, 151st Fortress Company, Węgierska Górka
With about 70 men in new bunkers he held the Soła valley against the German 7th Infantry Division from 1 to 3 September. Seriously wounded and captured on 3 September, he spent the war in German prisoner-of-war camps.
Chapter 3 →Hero of September
Stanisław Maczek
Colonel, 10th Motorized Cavalry Brigade
He held the Germans in the Beskids from the first day and led a fighting withdrawal that brought most of his men into Hungary. In exile he formed the 1st Armoured Division, which helped close the Falaise pocket and liberated Breda.
Chapter 3 →Special unit
The Volhynian Cavalry Brigade
Col. Julian Filipowicz, Army Łódź
Fighting dismounted with 37 mm Bofors guns, anti-tank rifles and armored train no. 53, it held the 4th Panzer Division at Mokra on 1 September, lost about 500 men killed and wounded, and pulled back about 12 km overnight.
Chapter 3 →Special unit
The 18th Pomeranian Uhlans
Pomeranian Cavalry Brigade, garrison Grudziądz
Its charge at Krojanty on 1 September, against infantry and not tanks, became the source of the most famous myth of the campaign. It fought on in the Tuchola Forest and ceased to exist as a cohesive unit on 4 September.
Chapter 3 →
IllustrationSpecial unit
The Black Brigade
10th Motorized Cavalry Brigade
Poland’s first fully motorized formation, organized in 1937, fought from the first day around Jordanów and Wysoka. It lost about half its strength but was never routed, and crossed into Hungary about 19 September.
Chapter 3 →Photographs, via Wikimedia Commons: Black Brigade: Capt. L. Stankiewicz of the brigade staff, from Wojna obronna Polski 1939 (1979), public domain. Badges are illustrations.
The air war
Read chapter 4 →
Hero of September
Stefan Pawlikowski
Colonel, commander of the Pursuit Brigade
His five escadrilles flew some 360 sorties over Warsaw in the first six days of the war and were credited with more than forty German aircraft. He escaped to France and Britain and was killed near Caen on 15 May 1943.
Chapter 4 →Hero of September
Władysław Gnyś
Second lieutenant, 121st Fighter Escadrille
On the morning of 1 September, minutes after his commander was shot down, he attacked two Do 17 bombers that crashed at Żurada, generally credited as the first Allied air victories of the war. He later flew in France and Britain.
Chapter 4 →
IllustrationSpecial unit
The Pursuit Brigade
Brygada Pościgowa, Warsaw
The fighter reserve defending the capital, with 54 fighters on 1 September. It met three raids that day and was credited with about 42 German aircraft in six days over Warsaw, for the loss of 38 of its fighters.
Chapter 4 →
IllustrationSpecial unit
The Bomber Brigade
Brygada Bombowa, Col. Władysław Heller
With 36 PZL.37 Łoś and 50 PZL.23 Karaś bombers it attacked German armored columns from 2 September. Its Łoś crews flew about 135 sorties and dropped about 119 tons of bombs; 17 to 19 Łoś reached Romania.
Chapter 4 →
IllustrationSpecial unit
The 111th Kościuszko Escadrille
III/1 Squadron, Pursuit Brigade
It traced its line to the 7th Air Escadrille, joined at Lwów in 1919 by American volunteers under Merian C. Cooper and Cedric Fauntleroy. In September 1939 it was credited with 8 German aircraft for the loss of 9 fighters.
Chapter 4 →Photographs, via Wikimedia Commons: Pawlikowski, public domain; PZL P.11a fighters, Ilustrowany Kuryer Codzienny, 1939; PZL.37 Łoś crews, 1939; the original Kościuszko badge from a Lwów collection; all public domain.
The northern front
Read chapter 5 →
Hero of September
Władysław Raginis
Captain, commander of the Wizna sector
From 2 September he commanded the bunkers on the Narew at Wizna. With Lt. Stanisław Brykalski he swore not to give up his post alive; on 10 September he ordered the last two bunkers to surrender and killed himself.
Chapter 5 →
Hero of September
Konstanty Plisowski
Brigadier general, defender of Brześć
A retired cavalry general, he volunteered at Brześć and with about 2,000 to 2,500 men held the citadel against Guderian’s corps from 14 to 16 September. He was murdered by the NKVD at Kharkiv in the spring of 1940.
Chapter 5 →
IllustrationSpecial unit
The Wizna garrison
Odcinek “Wizna,” Operational Group “Narew”
Between about 350 and 720 men, by different counts, in some twelve to sixteen works on the Narew and Biebrza. They held the crossings against the 10th Panzer Division and the Lötzen Brigade from 7 September until about midday on 10 September.
Chapter 5 →Photographs, via Wikimedia Commons: Raginis and Plisowski, public domain; Raginis’s bunker at Góra Strękowa, 2008, Nie na zarty, CC BY-SA 4.0.
Warsaw and the Bzura
Read chapter 6 →
Hero of September
Stefan Starzyński
President of the City of Warsaw
He refused to leave when the government went east and, as civil commissar from 8 September, ran the besieged city: food and water, the Civic Guard, fire brigades, shelter for refugees and the burial of the dead. He broadcast to the city until 23 September.
Chapter 6 →
Hero of September
Julien Bryan
American photographer and filmmaker
One of very few foreign journalists who stayed in besieged Warsaw, from 7 to 21 September, and apparently the only one with a movie camera. Life printed his photographs that October, and his film Siege was nominated for an Academy Award.
Chapter 6 →
Hero of September
Tadeusz Kutrzeba
General, commander of Army Poznań
He devised the Bzura counterattack and launched it on 9 September with his own army and Army Pomorze. He broke out to Warsaw on 22 September, became deputy commander of its defense and signed the capitulation on 28 September.
Chapter 6 →
IllustrationSpecial unit
The defenders of Warsaw
40th Infantry Regiment “Children of Lwów” and the garrison
Stopped in Warsaw on 7 September, the regiment’s battalions held the barricades of Wola and Ochota against the 4th Panzer Division on 8 and 9 September. The city held until 28 September and was awarded the Virtuti Militari.
Chapter 6 →Photographs, via Wikimedia Commons: Starzyński, public domain; Julien Bryan, Look, public domain; Kutrzeba arriving to negotiate the surrender, 1939, public domain; anti-aircraft gunners in Warsaw, CAF, public domain.
The coast and the navy
Read chapter 7 →
Hero of September
Stanisław Dąbek
Colonel, commander of the Land Coastal Defense
He led marines, reservists, police and volunteers in a defense of Gdynia and the Oksywie heights meant to last ten days that lasted nineteen. On 19 September, wounded and with his last position overrun, he ordered the fighting to stop and shot himself.
Chapter 7 →
Hero of September
Józef Unrug
Rear admiral, commander of the Fleet
He signed the Peking order and directed the defense of the coast and of Hel, which held until 2 October. In German captivity the former German naval officer refused to speak German. He died in exile in France in 1973.
Chapter 7 →
Hero of September
Jan Grudziński
Lieutenant commander, ORP Orzeł
He took command of the interned submarine at Tallinn on 15 September, broke out on the night of 17–18 September and reached Rosyth on 14 October without charts. He was lost with Orzeł in the North Sea in 1940, aged 32.
Chapter 7 →
IllustrationSpecial unit
The Gdynia Scythemen
Kosynierzy Gdyńscy, Land Coastal Defense
Gdynia workers the army could not arm with rifles took up war scythes and pikes, echoing Kościuszko’s scythemen of 1794. They fought west of the city and on the Oksywie heights, more and more with captured rifles; their numbers are disputed.
Chapter 7 →
IllustrationSpecial unit
The crew of ORP Orzeł
About 60 officers and men
Interned at Tallinn and stripped of their charts, they broke out under fire, released their two Estonian guards unharmed and crossed the Baltic and the Danish straits to Britain. Orzeł sank the transport Rio de Janeiro on 8 April 1940.
Chapter 7 →
IllustrationSpecial unit
The Hel Fortified Region
Rejon Umocniony Hel, Cmdr. Włodzimierz Steyer
About 2,800 to 3,000 men at the tip of the Hel peninsula. Planned to hold for about two weeks, they held for 32 days, dueled with the battleships Schleswig-Holstein and Schlesien and surrendered on 1–2 October.
Chapter 7 →Photographs, via Wikimedia Commons: Dąbek; the capitulation at Hel; Orzeł at Rosyth, 1940, and at Gdynia, 1939 (Witold Pikiel, NAC); Gdynia scythemen Andrzej and Jan Skibiński, from A. Bałaban (1979); the Laskowski battery, Coastal Defense Museum, Hel; all public domain.
The Soviet invasion and the last battles
Read chapter 8 →
Hero of September
Wilhelm Orlik-Rückemann
Brigadier general, commander of the Border Protection Corps
After 17 September he gathered his scattered border battalions into a fighting group, beat a Soviet division at Szack on 28 September and fought the KOP’s last battle at Wytyczno on 1 October. He died in Ottawa in 1986.
Chapter 8 →
Hero of September
Franciszek Kleeberg
Brigadier general, Independent Operational Group Polesie
From depots, reservists, border guards, river sailors and stragglers he built a force of 17,000 to 18,000 men, fought the Red Army and then the Germans at Kock, and surrendered on 6 October. He died in German captivity in 1941.
Chapter 8 →
Hero of September
Henryk Dobrzański “Hubal”
Major, Detached Unit of the Polish Army
A prewar international show-jumping rider, he refused to lay down his arms after the capitulation and kept a uniformed unit in the field for seven months. He was killed near Anielin on 30 April 1940.
Chapter 8 →
IllustrationSpecial unit
The Border Protection Corps
Korpus Ochrony Pogranicza (KOP)
Formed in 1924 to guard the eastern frontier, its posts were overrun within hours on 17 September, though some fought until their ammunition ran out. Gathered under Orlik-Rückemann, its battalions fought at Szack and Wytyczno.
Chapter 8 →Photographs, via Wikimedia Commons: Orlik-Rückemann, Kleeberg and Dobrzański, public domain; KOP watch post with President Mościcki, 1929, Witold Pikiel, NAC, public domain.
Exile and memory
Read chapter 9 →Hero of September
Jan Karski
Artillery officer and underground courier
Taken prisoner by the Red Army in September 1939, he escaped from a German transport and became a courier of the Polish Underground State. On 28 July 1943 he reported to Roosevelt at the White House. Yad Vashem recognized him as Righteous Among the Nations.
Chapter 9 →Hero of September
Witold Urbanowicz
Fighter pilot, commander of No. 303 Squadron
An instructor at Dęblin in September 1939, he made his way through Romania and France to Britain, led No. 303 Squadron and was credited with 15 victories in the Battle of Britain. He later flew with the U.S. 14th Air Force in China.
Chapter 9 →
IllustrationSpecial unit
No. 303 Squadron
No. 303 (Kościuszko) Polish Fighter Squadron, RAF
Formed at Northolt in August 1940 and operational from 31 August, it flew Hurricanes in the Battle of Britain with 126 claims, under the badge designed in 1919 by the American volunteer Lt. Elliott Chess.
Chapter 9 →Photographs, via Wikimedia Commons: Pilots of No. 303 Squadron, 1940, public domain. Badges are illustrations.
WWII art
Painted panels and insignia in the style of 1939.
Two fuselage panels in the manner of the period: a PZL P.11c fighter with a squadron badge on its side and the red-and-white checkerboard of the Polish Air Force, and a PZL.37 Łoś bomber with the Bomber Brigade’s badge. Below them, a badge for each unit and place in this collection, used on the hero and unit cards above and in the chapters.
- Pursuit BrigadeWarsaw, 1939
- Bomber BrigadePZL.37 Łoś
- Kościuszko Escadrille111th and No. 303
- Air Forcethe checkerboard
- Cipher BureauEnigma
- Westerplatte1–7 Sep
- Polish Post OfficeDanzig, 1 Sep
- Volhynian CavalryMokra
- 18th UhlansKrojanty
- Black Brigade10th Motorized Cavalry
- Wizna7–10 Sep
- Warsaw fights8–28 Sep
- Gdynia ScythemenOksywie
- Helto 2 Oct
- ORP OrzełTallinn
- Border Protection CorpsSzack
- Polish Armythe white eagle
Original illustrations in the period style — not official insignia.
The numbers and their variants
How big the armies were, and what the campaign cost.
Almost every figure in this campaign comes in more than one version. Armies are counted in the field or on paper, aircraft at the front or in all, the dead by official returns of 1939 or by later research. The solid part of each bar is the lower estimate and the hatched part runs to the higher one; the label gives the range. Each chart names its sources and links to the chapter that explains them.
Men under arms
German and Slovak forces on 1 September, Polish forces under arms, and the Red Army on 17 September.
Sources: Zaloga (2002); Kochanski (2012); Moorhouse (2019); IPN; Great Russian Encyclopedia (617,600 Soviet troops; other estimates about 450,000 to more than 800,000). Chapter 1 · Chapter 8
Tanks and aircraft, 1 September 1939
Most German tanks were light Panzer Is and IIs; most Polish armor was two-man tankettes.
Sources: Jentz via Panzerworld (2,690 German tanks with command tanks; other counts 2,500–2,750); IPN and Zaloga for Polish armor; Hooton and the Luftwaffe Quartermaster General (1,434 in Luftflotten 1 and 4; up to 2,315 counting all types); Cynk for 392 Polish front-line aircraft. Chapter 1 · Chapter 4
The dead, 1 September – 6 October 1939
Killed and missing in the campaign, by side.
Sources: PSZ, vol. 1, as used by Zaloga and Kochanski (Polish military dead); Hitler’s Reichstag speech of 6 October 1939 (10,572 German dead) and later German research (about 16,000); Krivosheev and Polish estimates (Soviet); civilian estimates as cited in the chapter. All are estimates. Chapter 9
Wounded, captured and escaped
The other side of the ledger.
Sources: Kochanski (2012); Moorhouse (2019); Soviet NKVD figures and the IPN; dzieje.pl after Batin, Przewoźnik and Roman (internees). Soviet documents count about 240,000 Polish prisoners; some Polish estimates are higher. Chapter 8 · Chapter 9
| Action | Polish | German |
|---|---|---|
| Westerplatte, 1–7 Sep | 182 to 210–240 men; about 15 killed | about 50 to about 300 killed, by different accounts |
| Polish Post Office, 1 Sep | about 56–60 people; 14 died; 38 executed 5 Oct | 8–10 killed |
| Wieluń, 1 Sep | 127 identified dead; estimates to about 1,200 or more | — |
| Mokra, 1 Sep | about 500 killed and wounded | about 800 men; 100–160 vehicles claimed, many recovered |
| Wizna, 7–10 Sep | 350–720 defenders; most killed, wounded or captured | dozens to low hundreds |
| The Bzura, 9–22 Sep | 14,000–20,000 killed; 100,000–170,000 captured | about 8,000 killed |
| Siege of Warsaw, 8–28 Sep | about 6,000 soldiers and 18,000–26,000 civilians killed | — |
| Hel, 1 Sep–2 Oct | about 50 killed and 150 wounded in most accounts | — |
| Kock, 2–5 Oct | 17,000–18,000 men; 16,860 surrendered 6 Oct | — |
Sources: Museum of the Second World War in Gdańsk and the IPN (Westerplatte, the Post Office, Wieluń); Sikorski Institute and Neumann (Mokra); Komorowski, Wesołowski and Zychowicz (Wizna); Cisowski and Zalewski, LeMO and the Museum of Warsaw (the Bzura and Warsaw); hela.com.pl (Hel); Wróblewski (Kock). Each chapter sets out the disagreements in detail.
Myths and the record
What popular memory gets wrong, and what the record shows.
Several of the best-known stories about September 1939 began as German propaganda, and others grew in the retelling at home. Each card sets the story against the evidence and links to the chapter that weighs it.
The myth
Polish cavalry charged German tanks with lances and sabers.
The record
At Krojanty on the evening of 1 September about 250 men of the 18th Pomeranian Uhlans charged a German infantry battalion in the open and scattered it before armored cars drove them off. No tanks were present. When Polish cavalry fought tanks, as at Mokra, they fought dismounted with anti-tank guns and rifles.
Zaloga; Moorhouse · Chapter 3The myth
The Polish Air Force was destroyed on the ground on the first day.
The record
The combat squadrons had moved to secret field airfields before 1 September. German bombs fell on the peacetime bases, wrecking trainers, reserve aircraft and hangars. Polish fighters fought for about two weeks and were credited with 126 German aircraft; the Bomber Brigade attacked the panzer columns.
Peszke; Cynk · Chapter 4The myth
Germany struck back after Polish attacks such as the raid on Gleiwitz.
The record
The “attacks” of 31 August were staged by the SS and SD on Heydrich’s orders, with Germans in Polish uniforms and murdered prisoners as props, as the organizer Alfred Naujocks testified at Nuremberg. The invasion had been planned since April and its date fixed weeks earlier.
IMT testimony of Naujocks · Chapter 1The myth
Poland collapsed in a few days.
The record
The campaign lasted five weeks, fought alone against two great powers attacking from three sides. Warsaw held until 28 September, Modlin until 29 September, Hel until 2 October and Kock until 6 October. France, with allies and the Maginot Line, asked for an armistice six weeks after 10 May 1940.
Frieser; Zaloga · Chapter 9The myth
At Wizna, 720 Poles held off 40,000 Germans and 350 tanks: Poland’s Thermopylae.
The record
The defense was real, stubborn and costly. But 40,000 is the strength of Guderian’s whole XIX Corps; the bunkers were attacked by the 10th Panzer Division and the Lötzen Brigade. The garrison numbered about 350 to 720, and German losses ran to dozens or low hundreds, not thousands.
Wesołowski; Zychowicz; IPN · Chapter 5The myth
The British broke Enigma alone, at Bletchley Park.
The record
The Polish Cipher Bureau reconstructed the military Enigma in December 1932 and read German traffic for years before the war. At Pyry in July 1939 it gave Britain and France its methods, the bomba design and two replica machines. Bletchley Park’s achievement was real and decisive, and it started from the Polish break.
Rejewski; Kozaczuk; GCHQ · Chapter 1Questions readers ask
Short answers, and eighty more in the FAQ.
The Invasion of Poland FAQ answers eighty questions in fourteen groups, from Danzig and the pact to the last battles, the occupation, the American connections and how to trace a Polish soldier of 1939.
When exactly did the invasion begin and end?
German dive bombers attacked the Tczew bridge positions at about 04:34 on 1 September 1939 and Wieluń at 04:40 by Polish accounts; Schleswig-Holstein opened fire on Westerplatte at 04:45. The last large Polish force surrendered at Kock on 6 October.
Where were the first shots of the war fired?
Probably at Tczew, where Stukas struck at about 04:34; then Wieluń, at 04:40 by Polish accounts or 05:40 by German records; then Westerplatte, the first naval bombardment of the war, at 04:45 to 04:48. Westerplatte became the symbol because it was the first battle fought as a battle.
How large were the armies?
About 1.5 million German and Slovak troops against about 1 million Polish soldiers; about 2,700 German tanks against about 880 Polish armored vehicles, most of them tankettes; and from 17 September a Red Army of perhaps 450,000 to 800,000.
Did Poland ever surrender?
No. The government crossed into Romania on the night of 17–18 September and was re-formed in Paris on 30 September. Warsaw, Modlin, Hel and Kleeberg’s group at Kock laid down their arms under local capitulations, not a national one.
Who broke Enigma?
The Polish Cipher Bureau: Marian Rejewski reconstructed the military machine in December 1932, and with Jerzy Różycki and Henryk Zygalski developed the methods that read German traffic for years. At Pyry in July 1939 they handed them to Britain and France.
Did Polish cavalry charge German tanks?
No. At Krojanty the 18th Pomeranian Uhlans charged German infantry and were then shot up by armored cars; reporters who saw the field the next day, with tanks that had arrived later, wrote of a charge against tanks, and German propaganda spread it.
Sources and photo credits
How this collection was written.
The chapters draw on the standard histories in English and Polish, the official Polish history of the campaign, published German and Soviet records, museum research and contemporary American documents. Where sources disagree on times, numbers or commanders, the chapters give the range and say who says what, and they distinguish contemporary evidence from later recollection and reconstruction.
Photographs are archival images from the Narodowe Archiwum Cyfrowe, the IPN, the Bundesarchiv, the Nationaal Archief, the National Library of Poland and published Polish works, with modern photographs under Creative Commons licenses, all via Wikimedia Commons and credited where they appear. Several German photographs of 1939 were made for propaganda and are captioned as such. Badges, nose art, maps and the effects in the opening scene are illustrations made for this collection.
- Steven J. Zaloga, Poland 1939: The Birth of Blitzkrieg (Osprey, 2002); Robert Forczyk, Case White: The Invasion of Poland 1939 (Osprey, 2019); Richard Hargreaves, Blitzkrieg Unleashed (2008).
- Roger Moorhouse, First to Fight: The Polish War 1939 (Bodley Head, 2019; U.S. ed. Poland 1939, Basic Books, 2020); Halik Kochanski, The Eagle Unbowed: Poland and the Poles in the Second World War (2012).
- Polskie Siły Zbrojne w II Wojnie Światowej, vol. 1, Kampania wrześniowa 1939 (Sikorski Institute); Apoloniusz Zawilski, Bitwy polskiego września.
- Jerzy B. Cynk, The Polish Air Force at War (1998); Michael Alfred Peszke, The Polish Navy 1918–1945 and articles in Military Affairs; Władysław Kozaczuk, Enigma (1984); Marian Rejewski’s accounts.
- Jochen Böhler, Auftakt zum Vernichtungskrieg (2006); Karl-Heinz Frieser, The Blitzkrieg Legend; G. F. Krivosheev, Soviet Casualties and Combat Losses (1997); Anna Cienciala, Natalia Lebedeva and Wojciech Materski, Katyn: A Crime Without Punishment (2007).
- Institute of National Remembrance (IPN); Museum of the Second World War in Gdańsk; Westerplatte Museum; Museum of the Polish Post, Gdańsk; Polish Aviation Museum, Kraków; Coastal Defense Museum, Hel; Museum of Warsaw.
- Foreign Relations of the United States, 1939; Franklin D. Roosevelt’s appeal of 1 September 1939 (American Presidency Project); Trial of the Major War Criminals before the International Military Tribunal (Nuremberg); Nazi–Soviet Relations 1939–1941 (U.S. Department of State, 1948).
- Full source lists for each subject are at the end of each chapter: 1 · 2 · 3 · 4 · 5 · 6 · 7 · 8 · 9.
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