Polish resistance movement in World War II in the context of "Massacre of Lwów professors"

During World War II, Poland was occupied by Nazi Germany and the Soviet Union (and Slovakia) following the invasion in September 1939, and it was formally concluded with the defeat of Germany by the Allies in May 1945. Throughout the entire course of the occupation, the territory of Poland was divided between Nazi Germany and the Soviet Union (USSR), both of which intended to eradicate Poland's culture and subjugate its people. In the summer-autumn of 1941, the lands which were annexed by the Soviets were overrun by Germany in the course of the initially successful German attack on the USSR. After a few years of fighting, the Red Army drove the German forces out of the USSR and crossed into Poland from the rest of Central and Eastern Europe.

Sociologist Tadeusz Piotrowski argues that both occupying powers were hostile to the existence of Poland's sovereignty, people, and the culture and aimed to destroy them. Before Operation Barbarossa, Germany and the Soviet Union coordinated their Poland-related policies, most visibly in the four Gestapo–NKVD conferences, where the occupiers discussed their plans to deal with the Polish resistance movement.

The Warsaw Uprising (Polish: powstanie warszawskie; German: Warschauer Aufstand), sometimes referred to as the August Uprising (Polish: powstanie sierpniowe), or the Battle of Warsaw, was a major World War II operation by the Polish underground resistance to liberate Warsaw from German occupation. It occurred in the summer of 1944, and it was led by the Polish resistance Home Army (Polish: Armia Krajowa). The uprising was timed to coincide with the retreat of the German forces from Poland ahead of the Soviet advance. While approaching the eastern suburbs of the city, the Red Army halted combat operations, enabling the Germans to regroup and defeat the Polish resistance and to destroy the city in retaliation. The Uprising was fought for 63 days with little outside support. It was the single largest military effort taken by any European resistance movement during World War II. The defeat of the uprising and suppression of the Home Army enabled the pro-Soviet Polish administration, instead of the Polish government-in-exile based in London, to take control of Poland afterwards. Poland would remain as part of the Soviet-aligned Eastern Bloc throughout the Cold War until 1989.

The Uprising began on 1 August 1944 as part of a nationwide Operation Tempest, launched at the time of the Soviet Lublin–Brest Offensive. The main Polish objectives were to drive the Germans out of Warsaw while helping the Allies defeat Germany. An additional, political goal of the Polish Underground State was to liberate Poland's capital and assert Polish sovereignty before the Soviet Union and Soviet-backed Polish Committee of National Liberation, which already controlled eastern Poland, could assume control. Other immediate causes included a threat of mass German round-ups of able-bodied Poles for "evacuation"; calls by Radio Moscow's Polish Service for uprising; and an emotional Polish desire for justice and revenge against the enemy after five years of German occupation.

The destruction of Warsaw was Nazi Germany's razing of the city in late 1944, after the 1944 Warsaw Uprising of the Polish resistance. The uprising infuriated German leaders, who decided to destroy the city in retaliation.

The razing of the city had long been planned. Warsaw had been selected for destruction and major reconstruction as part of the Nazis' planned Germanization of Central Europe, under the Nazi Generalplan Ost. However, by late 1944, with the war clearly lost, the Germans had abandoned their plans of colonizing the East. Thus, the destruction of Warsaw did not serve any military or colonial purpose; it was carried out solely as an act of reprisal.

The Home Army (Polish: Armia Krajowa, pronounced [ˈarmja kraˈjɔva]; abbreviated AK) was the dominant resistance movement in German-occupied Poland during World War II. The Home Army was formed in February 1942 from the earlier Związek Walki Zbrojnej (Armed Resistance) established in the aftermath of the German and Soviet invasions in September 1939. Over the next two years, the Home Army absorbed most of the other Polish partisans and underground forces. Its allegiance was to the Polish government-in-exile in London, and it constituted the armed wing of what came to be known as the Polish Underground State. Estimates of the Home Army's 1944 strength range between 200,000 and 600,000. The latter number made the Home Army not only Poland's largest underground resistance movement but, along with Soviet and Yugoslav partisans, one of Europe's largest World War II underground movements.

The Home Army sabotaged German transports bound for the Eastern Front in the Soviet Union, destroying German supplies and tying down substantial German forces. It also fought pitched battles against the Germans, particularly in 1943 and in Operation Tempest from January 1944. The Home Army's most widely known operation was the Warsaw Uprising of August–October 1944. The Home Army also defended Polish civilians against atrocities by Germany's Ukrainian and Lithuanian collaborators. Its attitude toward Jews remains a controversial topic.

Nazi crime or Hitlerite crime (Polish: zbrodnia nazistowska or zbrodnia hitlerowska) is a legal concept used in the Polish legal system, referring to an action which was carried out, inspired, or tolerated by public functionaries of Nazi Germany (1933–1945) that is also classified as a crime against humanity (in particular, genocide) or other persecutions of people due to their membership in a particular national, political, social, ethnic or religious group.

Nazi crimes in Poland were perpetrated against tens of millions of Polish people and caused the deaths of millions, especially Jews, members of the resistance, Romani people, socialists, and homosexuals. Millions of non-Polish Holocaust victims and Soviet prisoners of war were also subjected to Nazi atrocities after being brought to Poland.

Operation Tempest or Operation Burza (Polish: akcja „Burza”, sometimes referred to in English as "Operation Storm") was a series of uprisings conducted during World War II against occupying German forces by the Polish Home Army (Armia Krajowa, abbreviated AK), the dominant force in the Polish resistance.

Operation Tempest's objective was to seize control of German-occupied cities and areas while the Germans were preparing their defenses against the advancing Soviet Red Army. The Polish Underground State hoped to take power before the Soviets arrived.

The Polish Underground State (Polish: Polskie Państwo Podziemne, also known as the Polish Secret State) was a single political and military entity formed by the union of resistance organizations in occupied Poland that were loyal to the Government of the Republic of Poland in exile in London. The first elements of the Underground State were established in the final days of the German and Soviet invasion of Poland, in late September 1939. The Underground State was perceived by supporters as a legal continuation of the pre-war Republic of Poland (and its institutions) that waged an armed struggle against the country's occupying powers: Nazi Germany and the Soviet Union. The Underground State encompassed not only military resistance, one of the largest in the world, but also civilian structures, such as justice, education, culture and social services.

Although the Underground State enjoyed broad support throughout much of the war, it was not supported or recognized by the communists and some of the right-wing extremists. The influence of the communists eventually declined amid military reversals (most notably, the failure of the Warsaw Uprising) and the growing hostility of the USSR. The Soviet Union had created an alternative, puppet government in 1944 (the Polish Committee of National Liberation) and ensured it formed the basis of the post-war government in Poland. During the Soviet-backed communist takeover of Poland at the end of the war, many Underground State members were prosecuted as alleged traitors and died in captivity. Abandoned by the Western Allies, finding it impossible to negotiate with the Soviets, and wishing to avoid a civil war, the key institutions of the Underground State dissolved themselves in the first half of 1945.