Poland (1939–1945)

Poland (1939–1945)
Conventional long name	Second Polish Republic (1939–1945)
Common name	Poland
Era	World War II
Status	Occupied and contested territory
Government type	Government-in-exile Polish government
Event start	Invasion of Poland
Date start	1 September 1939
Event end	Yalta and Potsdam settlements
Date end	1945
Capital	Warsaw (occupied)
Leaders	Ignacy Mościcki, Władysław Sikorski, Bolesław Bierut
Population estimate	Prewar ~35 million

Poland (1939–1945) was the central European state whose territory and people were devastated by the Invasion of Poland and subsequent occupation by Nazi Germany and the Soviet Union during World War II. The period saw catastrophic human losses, the destruction of cities such as Warsaw, the dismantling of prewar institutions including the Polish Legions and Sanation, and the emergence of a Polish government-in-exile and underground Home Army resisting both occupiers.

Background and prewar Poland

The Second Polish Republic emerged after World War I via the Treaty of Versailles, Polish–Soviet War, and borders shaped by the Curzon Line debates and the Minority Treaties. Political life featured leaders and movements such as Józef Piłsudski, the Sanation movement, Roman Dmowski, the National Democratic movement, and parties like Polish Socialist Party and Peasant Party. Economic and social tensions involved regions such as Silesia, Eastern Galicia, and Vilnius Region, with minorities including Polish Jews, Ukrainians, and Belarusians; international relations involved Nazi Germany, Soviet Union, France, United Kingdom, and the League of Nations.

Invasion and occupation (1939)

On 1 September 1939 Wehrmacht forces invaded across the Polish Corridor and attacked cities such as Gdańsk (Danzig) and Warsaw, initiating the Polish Defensive War. On 17 September 1939 the Soviet invasion of Poland from the east, coordinated under the Molotov–Ribbentrop Pact, led to swift collapse despite battles like the Battle of Bzura and the defense of Westerplatte. The Polish September Campaign ended with the Capitulation of Warsaw and mass movements such as the Evacuation of Polish gold to Romania and France, while the Polish Underground State began to form under leaders connected to Władysław Sikorski and General Michał Karaszewicz-Tokarzewski.

German and Soviet occupation policies

Under General Government administration led by Hans Frank, Nazi policies included forced labor, Germanization, and the creation of Auschwitz concentration camp, Treblinka extermination camp, and Majdanek as sites of mass murder and exploitation. The Soviet Union conducted mass deportations to Siberia and Kazakhstan, extrajudicial killings such as the Katyn massacre carried out by the NKVD, and incorporation of eastern territories into the Ukrainian Soviet Socialist Republic and Belarusian SSR. Both occupiers implemented policies affecting institutions like Jagiellonian University, Warsaw University, and religious life centered on Roman Catholic Church in Poland and communities led by figures such as Cardinal August Hlond.

Polish resistance and the Home Army

The Armia Krajowa became the principal resistance force inside occupied Poland, linked to the Polish Underground State and loyal to the Polish government-in-exile in London. Operations included sabotage against Reich Railway targets, intelligence passed to SIS and SOE, and uprisings such as the Warsaw Uprising of 1944 coordinated by commanders like Tadeusz Bór-Komorowski and planners from Operation Tempest. Other groups included Armia Ludowa aligned with Polish Workers' Party, nationalist organizations like National Armed Forces, and partisan units fought in forests near Białystok, Lublin, and Kielce.

The Holocaust and persecution of Jews and minorities

Nazi policies produced ghettos in Łódź Ghetto, Warsaw Ghetto, and Kraków Ghetto and systematic extermination through camps including Bełżec, Sobibór, and Chelmno. Jewish leadership figures such as the Jewish Combat Organization led uprisings in Warsaw Ghetto Uprising, aided by contacts with the Żegota Council and individuals like Irena Sendler. Persecution also targeted Roma, Sinti, Polish intelligentsia during Intelligenzaktion, and clergy including victims like Maximilian Kolbe; collaboration, rescue, and complicity involved actors across regions such as Volhynia and Podlachia with groups like Ukrainian Insurgent Army implicated in massacres such as Volhynia massacres.

Military campaigns and exile government

Polish armed forces reconstituted abroad in France and later United Kingdom, forming units like the Polish Air Force squadrons in the Battle of Britain including No. 303 Squadron RAF, and armored formations with the II Corps under Władysław Anders that fought at the Battle of Monte Cassino. Diplomatic efforts involved Władysław Sikorski until his death in the Gibraltar B-24 crash, and negotiations at conferences such as Tehran Conference, Yalta Conference, and Potsdam Conference influenced recognition of postwar authorities like Provisional Government of National Unity and led to tensions with leaders including Joseph Stalin, Winston Churchill, and Harry S. Truman.

Postwar consequences and border changes

After 1945 borders shifted west under agreements at Tehran Conference and Potsdam Conference, moving the eastern frontier to the Curzon Line and assigning former German territories such as Silesia, Pomerania, and Masuria to Polish administration, while cities like Kraków, Lviv (Lwów), and Vilnius were affected by transfers to the Soviet Union and Lithuanian SSR. Population transfers included expulsions of ethnic Germans from regions like Opole and resettlement of Poles from Kresy into formerly German areas, overseen by entities including Allied Control Commission and administrators like Bolesław Bierut. The wartime destruction shaped the creation of the Polish People's Republic under communist structures influenced by Polish Workers' Party and Sovietization policies, while survivors, veterans, and émigré communities linked to organizations such as Union of Polish Patriots and diaspora centers in London and New York City preserved competing interpretations of wartime experience.

Category:History of PolandCategory:World War II by country