Around six million Polish citizens are estimated to have perished during World War II. Most were civilians killed by the actions of Nazi Germany, the Soviet Union, the Lithuanian Security Police, as well as the Organization of Ukrainian Nationalists and its offshoots (the Ukrainian Insurgent Army, the Self-defense Kushch Units and the Ukrainian People's Revolutionary Army).
At the International Military Tribunal held in Nuremberg, Germany, in 1945–46, three categories of wartime criminality were juridically established: waging a war of aggression; war crimes; and crimes against humanity. For the first time in history, these three categories of crimes were defined after the end of the war in international law as violations of fundamental human values and norms, regardless of internal (local) law or the obligation to follow superior orders. In subsequent years, the crime of genocide was elevated to a distinct, fourth category.
These crimes were committed in occupied Poland on a tremendous scale, unparalleled elsewhere in Europe.
German-Soviet partitioning of Poland and cooperation (September 1939 – June 1941)
Following 1 September 1939 invasion of Poland from the west by Germany, the Soviets attacked from the east on 17 September in accordance with the terms of the Molotov–Ribbentrop Pact, a secret non-aggression agreement signed in August. Within a month, Poland had been divided between two occupational forces, and their joint victory parade was held in Brest-Litovsk. Germany annexed 91,902 km2 (35,484 sq mi) with 10 million citizens and controlled the newly created General Government, which consisted of a further 95,742 km (59,491 mi) with 12 million citizens. In total, Germany's zone of occupation consisted of 187,644 km2 (72,450 sq mi) with 22 million citizens. The Soviet Union occupied 202,069 km2 (78,019 sq mi) with over 13 million citizens. In 1939, the invading forces consisted of 1.5 million Germans and nearly half a million Soviets.
Poland's territory was divided between Nazi Germany and the USSR, and was governed directly by the occupying countries, without establishing any form of Polish collaborating puppet authorities. The occupying powers' actions eclipsed the sovereign Polish state, whose government went into exile, and inflicted massive damage to the country's cultural heritage. Other war crimes against Poland included deportations aimed at ethnic cleansing, imposition of forced labor, pacifications, and genocidal acts. There were many similarities between the two zones of occupations marked by systematic oppression. Both invaders executed Polish civilians and prisoners of war in parallel campaigns of ethnic cleansing, coordinating some of these actions through Gestapo–NKVD conferences. "The scale and extent of the brutality practised in occupied Poland far exceeded anything experienced in other occupied countries."
In the summer and autumn of 1941 the lands annexed in the east by the Soviets, containing large Ukrainian and Belarusian populations, were overrun by Nazi Germany in the initially successful Operation Barbarossa against the Soviet Union.
Nazi German crimes against the Polish nation
The invasion of Poland (September 1939)
From 1 September 1939, the war against Poland was intended as a fulfilment of the plan described by Adolf Hitler in his book Mein Kampf. The main goal of the plan was to make all of Eastern Europe into the Lebensraum (living space) of Greater Germany. German historian Jochen Böhler observed that the war of annihilation did not begin with the Final Solution, but immediately after the attack on Poland. In order to inspire rage against the Poles and trigger broad public acceptance for total war (that is, war with no legal or moral limitations), the Goebbels propaganda machine soon published and distributed throughout Germany two books based on falsified information: Dokumente polnischer Grausamkeit (Documents of Polish Brutality) and the Polnische Blutschuld (Polish Blood Guilt). A false flag operation, the Gleiwitz incident, was organised by the German agents to serve as the casus belli. Wehrmacht (the German armed forces) was sent out without a formal declaration of war "to kill without mercy and reprieve all men, women and children of the Polish race", as ordered by Adolf Hitler in his speech to military commanders on 22 August 1939. This could be seen as an attempt to destroy the entire nation. The invading Germans believed that the Poles were racially inferior to them.
Indiscriminate executions by firing squad
From the very beginning of war against Poland, German forces carried out massacres and executions of civilians. Many of these atrocities were not properly researched after the war due to the political divide between Eastern and Western Europe during the Cold War, wrote Böhler. Polish eyewitness accounts do not identify the German units involved; that information is traceable only through German records. Therefore, the crimes committed by the Wehrmacht (the regular German army) were often wrongly attributed to SS operational groups in Polish historiography. It is estimated that there were two hundred executions every day in September 1939. Reinhard Heydrich, head of the Reich Security Main Office, complained that the rate was too slow. Typically, the mass executions were conducted in public spaces such as the town square in order to inflict terror.
Records show that during the German advance across Poland 531 towns and villages were burned. By the end of September 1939 the names of settlements, dates and numbers of civilians executed by the Wehrmacht included: Starogard (2 September), 190 Poles, 40 of them Jews;[a] Świekatowo (3 September), 26 Poles;[b] Wieruszów (3 September), 20 Poles all Jews.[c] On 4 September 1939 the 42nd Infantry Regiment committed the Częstochowa massacre with 1,140 citizens or more, 150 of them Jews, murdered in wild shooting actions in several city locations, leading to a final bloodbath according to Polish reports, involving frightened and inexperienced troops opening machine gun fire at a crowd of 10,000 civilians rounded up as hostages in the Main Square.[d][f] The official Wehrmacht tally listed only 96 male and 3 female victims of the so-called "anti-partisan" action in the city.
In Imielin (4–5 September), 28 Poles were killed;[e] in Kajetanowice (5 September), 72 civilians were massacred in revenge for two German horses killed by German friendly fire;[f] Trzebinia (5 September), 97 Polish citizens;[g] Piotrków (5 September), Jewish section of the city was set on fire;[h] Będzin (8 September), two hundred civilians burned to death;[i] Kłecko (9–10 September), three hundred citizens executed;[j] Mszadla (10 September), 153 Poles;[k] Gmina Besko (11 September), 21 Poles;[l] Kowalewice (11 September), 23 Poles;[m] Pilica (12 September); 36 Poles, 32 of them Jewish;[n] Mielec (13 September), 55 Jews burned to death;[p] Piątek (13 September), 50 Poles, seven of them Jews;[n] Mień (13 September), 9 Poles; Olszewo (14 September), 13 people (half of the village) from Olszewo and 10 from nearby Pietkowo, Gabrysin and Marynki, along with 30 Polish prisoners of war; Moskwin (14 September), 9 Poles. On 14–15 September about 900 Polish Jews, mostly intelligentsia, were targeted in parallel shooting actions in Przemyśl and in Medyka; this was a foreshadowing of the Holocaust to come.[n] Roughly at the same time, in Solec (14 September), 44 Poles killed;[r] soon thereafter in Chojnice, 40 Polish citizens;[s] Gmina Kłecko, 23 Poles;[t] Bądków, 22 Poles;[u] Dynów, two hundred Polish Jews.[w] Public executions continued well beyond September, including in municipalities such as Wieruszów County, Gmina Besko, Gmina Gidle, Gmina Kłecko, Gmina Ryczywół, and Gmina Siennica, among others.
Along with civilians, captured Polish Army soldiers were also massacred. On the very first day of invasion (1 September 1939), Polish prisoners of war (POWs) were murdered by the Wehrmacht at Pilchowice, Czuchów, Gierałtowice, Bojków, Lubliniec, Kochcice, Zawiść, Ornontowice and Wyry; such atrocities would continue throughout the invasion. The German army did not consider captured servicemen to be combatants because they fought differently from them, often avoiding direct confrontation in favor of guerrilla tactics in the face of overwhelming force. Historian Tadeusz Piotrowski estimated over 1,000 POWs were executed by the Wehrmacht, while Timothy Snyder, an American historian wrote that over 3,000 Polish POWs were killed in 63 separate shooting actions in which they were often forced to take their uniforms off, an estimate shared by Jochen Böhler. On top of executions by regular troops, more mass killings were conducted in remote areas by the newly formed Einsatzgruppen totalling 3,000 men aided by the Selbstschutz volunteer executioners, bringing the total number of killing operations to 16,000 before the end of September 1939. Before the end of the year, over 45,000 Poles had been murdered in occupied territories.
Bombing campaigns
The invading German force was equipped with 2000 modern war planes, which were deployed on 1 September 1939 at dawn in Operation Wasserkante, thus opening the September Campaign against Poland; there was no declaration of war. The Luftwaffe's first sorties of the war targeted Polish cities with no military targets of any kind; for example, the city of Wieluń was destroyed almost completely by 70 tonnes of munitions dropped within several hours in spite of the fact that it had no strategic importance to the Germans, and the city of Warsaw was bombed as well.
The Luftwaffe took part in the mass killing by strafing refugees on the road. The number of civilians wounded or killed by aerial bombing is put at over 100,000. The Luftwaffe dropped thousands of bombs on urban centres inhabited only by civilian populations. Amongst the Polish cities and towns bombed at the beginning of war were Brodnica, Bydgoszcz, Chełm, Ciechanów, Kraków, Częstochowa, Grodno, Grudziądz, Gdynia, Janów, Jasło, Katowice, Kielce, Kowel, Kutno, Lublin, Lwów, Olkusz, Piotrków, Płock, Płońsk, Poznań, Puck, Radom, Radomsko, Sulejów, Warsaw, Wieluń, Wilno, and Zamość. Over 156 towns and villages were attacked by the Luftwaffe. Warsaw suffered particularly severely with a combination of aerial bombardment and artillery fire reducing large parts of its historic city centre to rubble. The Soviet Union assisted the Germans by allowing them to use a radio beacon from Minsk to guide their planes.
During the German invasion of Poland, the Einsatzgruppen (special action squads of SS and police) were deployed in the rear and arrested or murdered civilians who were caught offering resistance against the Germans or who were considered to be capable of doing so, as determined by their position and social status.
Extermination of Polish intelligentsia
Unternehmen Tannenberg
Immediately after invasion, the Germans employed the earlier prepared Special Prosecution Book-Poland to launch the Operation Tannenberg campaign of mass murders and concentration camps incarcerations. German army units and paramilitary Selbstschutz ("self-defense") forces composed of Volksdeutsche also participated in executions of civilians. The Selbstschutz, along with SS units, took an active part in the mass murders in Piaśnica, in which between 12,000 and 16,000 Polish civilians were murdered. In the city of Bydgoszcz, the Volksdeutscher Selbstschutz (German Fifth Column) attempted to aid the invading German forces by shooting at the Polish Army. A number of saboteurs were executed by the Poles for treason, including for possession of military weapons. The Nazi German government in its own communiqués dubbed the Bydgoszcz incident Bloody Sunday, and claimed the wholesale slaughter of Germans in the city, which was not true. When Bydgoszcz was taken over by the Wehrmacht in October, designated killing squads began murdering civilian Poles in revenge at the Valley of Death (Bydgoszcz); 136 Polish school boys including 12-year-olds with about 6000 others by end of 1939; some 20,000 were murdered in all. Other murder sites included Gniezno, 15 Polish townsmen including Father Zabłocki; Szamotuły (20 October), five Poles in a crowded spectacle at the city centre; Otorowo (7 November), 68 Polish intelligentsia including parish priest and a count; Kościan Leszno, 250 Poles; Śrem, 118 Poles; Wolsztyn, a group of Poles; Kórnik, 16 Polish citizens; Trzemeszno, 30 Polish citizens; Mogilno, 30/39 Poles and a Polish Jew; Antoninek, 20 Polish citizens shot. Other execution sites included Rawicz, Grodzisk Wielkopolski, Nowy Tomyśl, Międzychód, Żnin, Września, Chełmno, Chojnice, Kalisz and Włocławek. More than 16,000 members of the intelligentsia were murdered in Operation Tannenberg alone.