September

:1:

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposin ...

begins with the

invasion An invasion is a military offensive in which large numbers of combatants of one geopolitical entity aggressively enter territory owned by another such entity, generally with the objective of either: conquering; liberating or re-establishing con ...

Poland Poland, officially the Republic of Poland, is a country in Central Europe. It is divided into 16 administrative provinces called voivodeships, covering an area of . Poland has a population of over 38 million and is the fifth-most populous ...

Nazi Germany Nazi Germany (lit. "National Socialist State"), ' (lit. "Nazi State") for short; also ' (lit. "National Socialist Germany") (officially known as the German Reich from 1933 until 1943, and the Greater German Reich from 1943 to 1945) was ...

. The resulting

invasion of Poland The invasion of Poland (1 September – 6 October 1939) was a joint attack on the Republic of Poland by Nazi Germany and the Soviet Union which marked the beginning of World War II. The German invasion began on 1 September 1939, one week aft ...

lasts until October 6, 1939, when the final significant Polish military forces surrender at Kock. German operations are conducted under the operational plan ''Fall Weiss'', while in Poland the campaign is referred to as the Polish Defense War of 1939. :2: Polish forces at Wieluń surrender to the German 10th Army. :3: The Polish

Poznań Army Army Poznań ( pl, Armia Poznań) led by Major General Tadeusz Kutrzeba was one of the Polish Armies during the Invasion of Poland in 1939. Tasks Flanked by Armia Pomorze to the north and Łódź Army to the south, the Army was to provide fla ...

proposes an attack against the German 8th Army. The German flank is exposed, but the proposal is rejected. :4: The

Battle of Mława The Battle of Mława, otherwise known as the Defence of the Mława position, took place to the north of the town of Mława in northern Poland between 1 and 3 September 1939. It was one of the opening battles of the Invasion of Poland (1939), Inva ...

concludes as the Polish Modlin Army begins to retreat. :5: Polish forces around Piotrków surrender to the 10th Army. :6: Polish forces regroup along the

Narew The Narew (; be, Нараў, translit=Naraŭ; or ; Sudovian: ''Naura''; Old German: ''Nare''; uk, Нарва, translit=Narva) is a 499-kilometre (310 mi) river primarily in north-eastern Poland, which is also a tributary of the river Vis ...

Vistula The Vistula (; pl, Wisła, ) is the longest river in Poland and the ninth-longest river in Europe, at in length. The drainage basin, reaching into three other nations, covers , of which is in Poland. The Vistula rises at Barania Góra in ...

, and San Rivers.

Kraków Kraków (), or Cracow, is the second-largest and one of the oldest cities in Poland. Situated on the Vistula River in Lesser Poland Voivodeship, the city dates back to the seventh century. Kraków was the official capital of Poland until 1596 ...

falls to the German 14th Army. :7: The siege of Westerplatte concludes with the surrender of its remaining garrison. Polish supreme command relocates to

Brześć Brest ( be, Брэст / Берасьце, Bieraście, ; russian: Брест, ; uk, Берестя, Berestia; lt, Brasta; pl, Brześć; yi, בריסק, Brisk), formerly Brest-Litovsk (russian: Брест-Литовск, lit=Lithuanian Br ...

from

Warsaw Warsaw ( pl, Warszawa, ), officially the Capital City of Warsaw,, abbreviation: ''m.st. Warszawa'' is the capital and largest city of Poland. The metropolis stands on the River Vistula in east-central Poland, and its population is officia ...

. Defenses along the

begin withdrawal to the Bug River.

Tarnów Tarnów () is a city in southeastern Poland with 105,922 inhabitants and a metropolitan area population of 269,000 inhabitants. The city is situated in the Lesser Poland Voivodeship since 1999. From 1975 to 1998, it was the capital of the Tarnów ...

falls to the 14th Army. :8: The Siege of Warsaw begins the land phase with the arrival of German units in the suburbs. The air bombardment had begun at the start of the Campaign. The pocket at Radom is reduced by the 14th Army. :9: The

Battle of Bzura The Battle of the Bzura (or the Battle of Kutno) was the largest Polish counter-attack of the German invasion of Poland and was fought from 9 to 19 September.''The Second World War: An Illustrated History '', Putnam, 1975, Google Print snippet ...

begins with a counter-attack against the German 8th Army. :12:

Białystok Białystok is the largest city in northeastern Poland and the capital of the Podlaskie Voivodeship. It is the tenth-largest city in Poland, second in terms of population density, and thirteenth in area. Białystok is located in the Białystok Up ...

falls to the German 3rd Army :13: The

defenses are penetrated as German forces cross the river south of Warsaw. :14: Germany captures Gdynia and Brest-Litovsk.

Siedlce Siedlce [] ( yi, שעדליץ ) is a city in eastern Poland with 77,354 inhabitants (). Situated in the Masovian Voivodeship (since 1999), previously the city was the capital of a separate Siedlce Voivodeship (1975–1998). The city is situated b ...

is captured by the 3rd Army. :15: The heaviest fighting of the

concludes with the Germans having gained the advantage. In the east,

Przemyśl Przemyśl (; yi, פשעמישל, Pshemishl; uk, Перемишль, Peremyshl; german: Premissel) is a city in southeastern Poland with 58,721 inhabitants, as of December 2021. In 1999, it became part of the Subcarpathian Voivodeship; it was pr ...

is captured by the 14th Army. :16: The envelopment of

is completed. :17: The eastern front of the Campaign opens with the invasion of Poland by the

Soviet Union The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen national ...

. Kutno falls to the German 8th Army and

Brest-Litovsk Brest ( be, Брэст / Берасьце, Bieraście, ; russian: Брест, ; uk, Берестя, Berestia; lt, Brasta; pl, Brześć; yi, בריסק, Brisk), formerly Brest-Litovsk (russian: Брест-Литовск, lit=Lithuanian Br ...

(Brześć) falls to the 3rd Army. :18: Polish President

Ignacy Mościcki Ignacy Mościcki (; 1 December 18672 October 1946) was a Polish chemist and politician who was the country's president from 1926 to 1939. He was the longest serving president in Polish history. Mościcki was the President of Poland when Germany ...

and Commander-in-Chief Edward Rydz-Śmigły leave Poland for

Romania Romania ( ; ro, România ) is a country located at the crossroads of Central Europe, Central, Eastern Europe, Eastern, and Southeast Europe, Southeastern Europe. It borders Bulgaria to the south, Ukraine to the north, Hungary to the west, S ...

, where they are both interned; Russian forces reach

Vilna Vilnius ( , ; see also other names) is the capital and largest city of Lithuania, with a population of 592,389 (according to the state register) or 625,107 (according to the municipality of Vilnius). The population of Vilnius's functional u ...

and

. :19: Soviet forces capture

Wilno Vilnius ( , ; see also #Etymology and other names, other names) is the capital and List of cities in Lithuania#Cities, largest city of Lithuania, with a population of 592,389 (according to the state register) or 625,107 (according to the munic ...

. :20: German and Soviet forces meet near

. :22: Soviet forces capture

Lwów Lviv ( uk, Львів) is the largest city in western Ukraine, and the seventh-largest in Ukraine, with a population of . It serves as the administrative centre of Lviv Oblast and Lviv Raion, and is one of the main cultural centres of Ukraine ...

German–Soviet military parade in Brest-Litovsk The German–Soviet military parade in Brest-Litovsk (german: Deutsch-sowjetische Siegesparade in Brest-Litowsk, russian: Парад вермахта перед частями РККА в Бресте) was an official ceremony held by the troops ...

. :27: The Siege of Warsaw comes to an end as Polish forces surrender. German forces enter the city on October 1, 1939. :28: Polish

government in exile A government in exile (abbreviated as GiE) is a political group that claims to be a country or semi-sovereign state's legitimate government, but is unable to exercise legal power and instead resides in a foreign country. Governments in exile us ...

set up in Paris with Raczkiewicz and Władysław Sikorski as Commander-in-Chief.

October

:1: The

Hel Peninsula Hel Peninsula (; pl, Mierzeja Helska, Półwysep Helski; csb, Hélskô Sztremlëzna; german: Halbinsel Hela or ''Putziger Nehrung'') is a sand bar peninsula in northern Poland separating the Bay of Puck from the open Baltic Sea. It is loc ...

garrison surrenders to German forces. :2: The Battle of Kock begins with a German advance. :5: German victory parade is held in Warsaw. :6: The Battle of Kock ends with the surrender of defending Polish forces. This is the final significant military resistance to the German or Soviet invasions.

September

October

See also