War crimes in occupied Poland during World War II

From the very beginning of war against Poland, German forces carried out massacres and executions of civilians.[15] 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.[16] Polish eyewitness accounts do not identify the German units involved; that information is traceable only through German records. Therefore, the crimes committed by the Heer (the regular German army) were often wrongly attributed to SS operational groups in Polish historiography.[17] It is estimated that there were two hundred executions every day in September 1939.[18] Reinhard Heydrich, head of the Reich Main Security Office, complained that the rate was too slow.[18] Typically, the mass executions were conducted in public spaces such as the town square in order to inflict terror.[19]

Execution of 56 Polish civilians in Bochnia during the German takeover of Poland, 18 December 1939

Records show that during the German advance across Poland five hundred thirty-one towns and villages were burned.[20] 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.[21]

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] Olszewo (13 September), 13 people (half of the village) from Olszewo and 10 from nearby Pietkowo including women and children stabbed by bayonets, shot, blown up by grenades, and burned alive in a barn;^[o] Mielec (13 September), 55 Jews burned to death;^[p] Piątek (13 September), 50 Poles, seven of them Jews.^[n] 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,[22] Gmina Besko,[23] Gmina Gidle,[24] Gmina Kłecko,[25] Gmina Ryczywół,[26] and Gmina Siennica, among others.[27]

Public execution of 10 Polish hostages by German troops in Gąbin, 15 June 1941

In the town of Bydgoszcz, the Volksdeutscher Selbstschutz (German Fifth Column) attempted to aid the invading German forces by shooting at the Polish Army.[28][29] A number of saboteurs were executed by the Poles for treason, including for possession of military weapons.[30] The Nazi German government in its own communiqués dubbed the Bydgoszcz incident Bloody Sunday,[30][31] and claimed the wholesale slaughter of Germans in the city, which was not true.[30] 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); some 20,000 died in all.[32][33]

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.[34] 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 executed by the Heer on the first day, while Timothy Snyder, an American historian wrote that over 3,000 POWs were killed in 63 separate shooting actions in which they were often forced to take their uniforms off.[35] 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.[36] Before the end of the year, over 45,000 Poles had been murdered in occupied territories.[37][38]

Destruction of Warsaw, during the German aerial bombing campaign against the city, September 1939

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.[39]

The Luftwaffe took part in the mass killing by strafing refugees on the road.[40][41] The number of civilians wounded or killed by aerial bombing is put at over 100,000.[42] The Luftwaffe dropped thousands of bombs on urban centres inhabited only by civilian populations.[43] 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.[41][43][44][45][40] Over 156 towns and villages were attacked by the Luftwaffe.[44] Warsaw suffered particularly severely with a combination of aerial bombardment and artillery fire reducing large parts of its historic city centre to rubble.[46] The Soviet Union assisted the Germans by allowing them to use a radio beacon from Minsk to guide their planes.[47]

Exhumation of the Katyń forest massacre victims in 1943; murdered by the Soviet NKWD three years earlier in the spring of 1940

Following the invasion, in April and May 1940 the NKVD secret police perpetrated the single most notorious wartime atrocity against any prisoners of war held by the Soviet Union. In the Katyn massacre nearly twenty-two thousand Polish nationals were killed in mass executions simultaneously. They included army officers, political leaders, civil servants, government officials, intellectuals, policemen, landowners, and scores of ordinary soldiers.[60][61] The Katyn Forest near Smolensk, Russia, was the primary execution site where 4,443 officers (the entire Polish military echelon in the custody of the Soviets),[62][63] were murdered by the Soviet secret police.[64] The name Katyn is now associated with the systematic execution of up to 21,768 Polish citizens in several locations ordered through a single document, including at the Kozelsk prisoner-of-war camp as well as the Starobelsk and Ostashkov camps.[60][65][64]

Among the victims of the massacre were 14 Polish generals, including Leon Billewicz, Bronisław Bohatyrewicz, Xawery Czernicki (admiral), Stanisław Haller, Aleksander Kowalewski, Henryk Minkiewicz, Kazimierz Orlik-Łukoski, Konstanty Plisowski, Rudolf Prich (murdered in Lviv), Franciszek Sikorski, Leonard Skierski, Piotr Skuratowicz, Mieczysław Smorawiński and Alojzy Wir-Konas (promoted posthumously).[66]

Polish families deported during the Soviet occupation of Kresy. The number of Poles extracted from their homes and sent into barren land in Siberia exceeded 1.6 million

An estimated 1.2 to 1.7 million Polish nationals (entire families with children, women, men, and elderly) were loaded onto freight trains and deported to the eastern parts of the USSR, the Urals, and Siberia.[67] The Soviets used against Poles the same process of subjugation used against their own citizens for many years beforehand, especially mass deportations.[68] In 1940 and the first half of 1941, the Soviets removed Poles from their homes in four major waves.[2][69] The first deportation action took place from 10 February 1940 on,[70][71] with more than 220,000 victims,[72] sent to northern European Russia; the second, on 13–15 April 1940, affected 300,000 to 330,000 Poles,[72][73] sent primarily to Kazakhstan. The third wave, in June–July 1940, totalled 240,000–400,000 victims.[72] The fourth wave took place in June 1941, deporting 200,000 Poles including a large number of children.[74][75]

On top of deporting Polish citizens en masse, the Soviets forcibly drafted Polish men into the Red Army.[2] It is estimated that 210,000 young Polish males were conscripted as newly declared Soviet subjects following the annexation of Kresy.[76]

The invading Soviets set out to remove Polish cultural influences from the land under concocted premises of class struggle and dismantle the former Polish system of administration.[77] All Polish nationals in occupied territories were declared to be citizens of the Soviet Union starting on 29 November 1939.[78] Many Polish social activists and community leaders were eliminated through judicial murder, the unjustified use of capital punishment. Captured Poles were transported to the Soviet Ukraine where most of them were executed in the dungeons of the NKVD in Kharkiv, the second largest city in Ukraine.[79]

The Polish territories were split between the Ukrainian and Belorussian SSRs with Ukrainian and Belarusian declared as the official languages in local usage, respectively.[80] Religious education was forbidden. Schools were forced to serve as tools of communist indoctrination. Monuments were destroyed (for example, in Wołczyn, the remains of King Stanisław August Poniatowski were ditched), street names changed, bookshops closed, libraries burned and publishers shut down. Collections from Tarnopol, Stanisławów and Sokal were transported to Russian archives.[78] Soviet censorship was strictly enforced. Even the ringing of church bells was banned.[81] However, a small minority of Polish citizens of various ethnic backgrounds (i.e. Belarusians) welcomed the Soviet invasion in the hope of gaining political concessions.[50]

Taxes were raised and religious institutions were forced to close.[81] The Soviets replaced the zloty with the ruble, but gave them blatantly absurd equal value. Businesses were mandated to stay open and sell at pre-war prices, hence allowing Soviet soldiers to buy goods with rubles. Entire hospitals, schools and factories were moved to the USSR.[82]

Polish hostages unloaded for mass execution outside of Warsaw. In total about 2,000 Poles were murdered at the site, in secret executions between 7 December 1939 and 17 July 1941[92]

The large-scale pacification operations, sometimes called "anti-partisan actions", constituted the core policy of the Nazi regime against Poland and resulted in the death of approximately 20,000 people in less than two years following the invasion. They were mainly conducted in the areas of General Government, Pomerelia, in the vicinity of Wielkopolska,[93] and in the newly created Bialystok District.[94]

On 10 September 1939 the policy of collective punishment was introduced, resulting in destruction of villages and towns in the path of Polish defence lines. In Bogusze and in Lipówka in Suwałki County residents were massacred by the Wehrmacht as soon as the Poles retreated.[94] Some 30 other settlements in the vicinity were burned down in the counties of Bielsk, Wysokie Mazowieckie, Suwałki and Łomża, even though there were not used by the retreating Polish forces. Around Białystok 19 villages were completely destroyed. In Pietraszki elderly people and children were fired at from an army tank, while in the villages of Wyliny-Ruś, Drogoszewo and Rutki all civilians were summarily executed, including the elderly.[94]

Polish women being led by German soldiers to the execution site; Palmiry, 1940

Terror killings committed by uniformed troops across Poland continued and between 2 October – 7 November 1939, over 8,866 Poles were killed (53 of them Jews). Among the victims were in Otorowo (20 October), five or 19 Poles shot because a swastika flag was removed by someone;[95] Gniezno, 15 Polish townsmen including Father Zabłocki;[95] Bydgoszcz, 136 Polish school boys including 12-year-olds with about 6000 others by end of 1939;[96] Szamotuły (20 October), five Poles in a crowded spectacle at the city centre;[95] Otorowo (7 November), 68 Polish intelligentsia including parish priest and a count;[95][42] Warsaw (22 November), announcement of the first anti-Jewish legislation: 53 Jews executed in public as punishment for one einheimischen Polizisten (local policeman) assaulted on the street;[97] Wawer (27 December), 106/107 murdered;[2][98][99] Palmiry (December 1940 – July 1941), two thousand Poles during AB-Aktion;[52][97] 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;[100] Antoninek, 20 Polish citizens shot. Other execution sites included Rawicz, Grodzisk Wielkopolski, Nowy Tomyśl, Międzychód, Żnin, Września, Chełmno, Chojnice, Kalisz and Włocławek.[93]

In July 1939, a Nazi secret program called T-4 Euthanasia Program was developed in Germany with the intention of exterminating physically or mentally disabled people.[101] The program was put into practice in the occupied territories during the invasion of Poland. Initially, it was implemented according to the following plan: a German director took control over the psychiatric hospital; under the threat of execution no patient could be released; all were counted and transported from the hospital by trucks to an unknown destination. Each truck was accompanied by soldiers from special SS detachments who returned without the patients after a few hours. The patients were said to be transferred to another hospital, but evidence showed otherwise. The first action of this type took place on 22 September 1939 in Kocborowo at a large psychiatric hospital in the Gdańsk region.[101] A firing squad murdered six hospital employees, including a deputy director, along with their patients. By December, some 1800 patients from Kocborowo had been murdered and buried in the Szpegawski forest. In total, 7000 victims were buried there.[102] Another extermination action took place in October 1939 at a hospital in Owińska near Poznań where 1000 patients (children and adults) were killed, with 200 more executed a year later.[103]

In addition to executions by firing squad, other methods of mass murder were implemented for the first time at the hospital in Owińska. Some 400 patients, along with medical staff,[104] were transported to a military fortress in Poznań where, in Fort VII bunkers, they were gassed with carbon monoxide delivered in metal tanks.[105] Other Owińska hospital patients were gassed in sealed trucks by exhaust fumes. The same method was performed in Kochanówek Hospital near Łódź, where 2200 persons were killed between March–August 1940. This was the first successful test of mass murder using gas van poisoning and this technique was later used and perfected on many other psychiatric patients in occupied Poland and Germany. Starting in 1941, gas vans were used on inmates of the extermination camps. The total number of psychiatric patients murdered by the Nazis in occupied Poland between 1939 and 1945 is estimated to be more than 16,000, with an additional 10,000 patients dying of malnutrition and hunger. Additionally, approximately 100 out of 243 members of the Polish Psychiatric Association met the same fate as their patients.[105]

Captive Jews from Kraków Ghetto await slave labour on an open field behind barbed wire, 1939

While ethnic Poles were usually subject to selective persecution in an effort to discourage them from resisting the Germans, all ethnic Jews were targeted from the outset.[52] During the first 55 days of the occupation approximately 5,000 Polish Jews were killed.[45] As of 12 November 1939, all Jews over the age of 12,[106] or 14,[107] were forced to wear the Star of David.[106][107] They were legally banned from working in key industries and in government institutions; to bake bread, or to earn more than 500 zloty a month.[108] Initially, the Jews were killed at a lower rate than ethnic Poles.[107]

Inside occupied Poland, the Germans created hundreds of ghettos in which they forced Jews to live. These World War II ghettos were part of the German official policy of removing Jews from public life. The combination of excess numbers of inmates, unsanitary conditions and lack of food resulted in a high death rate among them.[52] The first ghetto was established in October 1939 at Piotrków.[109] Initially the ghettos were open but on 1 May the Łódź ghetto was closed by Germans sealing the Jews inside.[110][111] The Warsaw Ghetto was closed in November 1940.[98] The Germans started a reservation for Jews near Lublin.[97]

The Germans tried to divide the Poles from the Jews using several laws. One law was that Poles were forbidden from buying from Jewish shops; if they did so, they were subject to execution.[107] Maria Brodacka was the first Pole to be killed by the Germans for helping a Jew. The Germans used the incident to kill 100 Jews being held as hostages. At the start of the war 1335 Poles were killed for sheltering Jews.[97]

The Warsaw Ghetto was the largest of the Jewish ghettos located in the territory of General Government during World War II,[112] established by Nazi Germany in Warsaw, the pre-war capital of Poland. Between 1941 and 1943, starvation, disease and mass deportations to concentration camps and extermination camps such as during the Gross-aktion Warschau, reduced the population of the ghetto from an estimated 445,000[113][114] to approximately 71,000.[115] In 1943 the Warsaw Ghetto was the scene of the Warsaw Ghetto Uprising.[116][117] The ghetto was reduced to rubble.[118]

From 1940 to 1944, it is estimated that starvation and disease caused the death of 43,000 Jews imprisoned in the Holocaust ghettos.[76] Most Polish Jews subsequently perished in the German death camps. Towards the end of 1942, the mass extermination of Polish Jews had started with deportations from urban centres to death camps including Jews from outside Poland.[119]

Germans looting the Zachęta National Gallery of Art and Museum in Warsaw, summer 1944

As part of the concerted effort to destroy Polish cultural heritage, the Germans closed universities, schools, museums, public libraries, and dismantled scientific laboratories.[2][120] They tore down monuments to national heroes.[121] Leading Polish academic institutions were reestablished as German. By the end of 1942 over 90 percent of the world-class art previously in Poland – as estimated by the German officials – was put into their own possession.[122] The Polish language had been banned in Wartheland; children were forced to learn the basics of German under harsh physical punishment. To prevent the emergence of a next generation of educated Poles, German officials decreed that the schooling of Polish youth would end at the elementary level.[121][123]

A basic issue in the solution of all these problems is the question of schooling and thus the question of sifting and selecting the young. For the non-German population of the East there must be no higher school than the four-grade elementary school. The sole goal of this school is to be-- Simply arithmetic up to 500 at the most; writing of one's name; the doctrine that it is a divine law to obey the Germans and to be honest, industrious, and good. I don't think that reading is necessary.

— Himmler's secret memorandum "Reflections on the Treatment of Peoples of Alien Races in the East"[124]

In his capacity as Reich Commissioner, Heinrich Himmler oversaw the kidnapping of Polish children to be Germanised. Historians estimate that between 50,000 and up to 200,000 Polish children were taken from their families during the war. They were sent to farms and families in the Reich never to return.[86][125] Many of the children remained in Germany after the war unaware of their true origin.[52]

At the end of October 1939, the Germans introduced the death penalty for active disobedience to the German occupation.[97] Plans for mass expulsions and the system of slave labour camps for up to 20 million Poles were made. Himmler thought of moving all Poles to Siberia.[126] In May 1940 he wrote a memorandum;[84] in it, he promised to eventually deport all Poles to the east. Most of them were intended to die during the cultivation of the swamps.[127]

Mass expulsion of Poles, as part of the German ethnic cleansing of western Poland annexed to the Reich, 1939

The Germans planned to change ownership of all property in the land incorporated into the Third Reich. In a speech to German colonists, Arthur Greiser said: "In ten years there will not even be a peasant smallholding which will not be in German hands". In the Wartheland, the Nazi goal was complete Germanization. The formerly Polish territories were to become politically, culturally, socially, and economically German.[128] The Nazis closed elementary schools where Polish was the language taught. Streets and cities were renamed (Łódź became Litzmannstadt, etc.). Tens of thousands of Polish enterprises from large industrial firms to small shops, were seized without payment to the owners.[129] Signs posted in public places warned: "Entrance forbidden for Poles, Jews, and dogs." The forced resettlement affected two million Poles. In the severe winter of 1939–40 families were made to leave behind almost everything without any recompense.[120] As part of Operation Tannenberg alone, 750,000 Polish peasants were forced out of their homes which were levelled, and the land given to German colonists and servicemen.[130] A further 330,000 were murdered.[131]

Jews were treated slightly differently as they were gathered together into ghettos in the cities.[85] Himmler ordered all Jews in the annexed lands to be deported to central Poland. In winter 1939–40, about 100,000 Jews were deported.[132]

All Polish males were required to perform forced labour.[86] Between 1939 and 1945, at least one and a half million Polish citizens were detained and transported to the Reich for forced labour against their will.[86] One estimate has one million (including POWs) from annexed lands and 1.28 million from the General Government.[133][134] The Polish Ministry of Foreign Affairs believes the figure was more than two and half million during the war.[52] Many were teenage boys and girls. Although Germany also used forced labourers from Western Europe, Poles, along with other Eastern Europeans viewed as inferior,[86] were subject to especially harsh discriminatory measures. They were forced to wear identifying purple Ps sewn to their clothing, subjected to a curfew, and banned from public transport. While the treatment of factory workers or farm hands often varied depending on the individual employer, Polish labourers as a rule were compelled to work longer hours for lower wages than Western Europeans,[135] and in many cities, they were forced to live in segregated barracks behind barbed wire. Social relations with Germans outside work were forbidden and sexual relations with them were considered "racial defilement", punishable by death.[136] During the war, hundreds of Polish men were executed for their relations with German women.[137]

Płaszów concentration camp outside Kraków, 1942

Citizens of Poland, but especially ethnic Poles and Polish Jews, were imprisoned in nearly every camp of the extensive concentration camp system in German-occupied Poland and in the Reich. A major labour camp complex at Stutthof, east of Gdańsk/Danzig was begun as an internment camp in September 1939.[138] An estimated 20,000 Poles died there as a result of hard labour, executions, disease and starvation. Some 100,000 Poles were deported to Majdanek concentration camp with subcamps in Budzyn, Trawniki, Poniatowa, Kraśnik, Puławy, as well as the "Airstrip", and Lipowa added in 1943. Tens of thousands of prisoners died there. An estimated 20,000 Poles died at Sachsenhausen outside Poland, 20,000 at Gross-Rosen, 30,000 at Mauthausen, 17,000 at Neuengamme, 10,000 at Dachau, and 17,000 at Ravensbrück.[84] In addition, tens of thousands of Polish people were executed or died in their thousands at other camps, including special children's camps such as in Łódź and its subcamp at Dzierżązna,[139] in prisons and other places of detention inside and outside Poland.

The Auschwitz concentration camp went into operation on 14 June 1940. The first transport of 728 Polish prisoners consisted mostly of schoolchildren, students and soldiers from the overcrowded prison at Tarnów. Within a week another 313 arrived. There were 1666 major transports in August and 1705 in September. This Polish phase of Auschwitz lasted until the middle of 1942.[140] By March 1941, 10,900 prisoners were registered at the camp, most of them Poles.[141]

The most notorious concentration camps in occupied Poland as well as along Nazi German borders included: Gross-Rosen in Silesia, now part of Poland,[142] Janowska, Kraków-Płaszów, Poniatowa (reassigned from forced labour camp),[143] Skarżysko-Kamienna, Soldau, Stutthof,[142] and Trawniki.[143]

The camp system where Poles were detained, imprisoned and forced to labour, was one of fundamental structures of the Nazi regime, and with the invasion of Poland became the backbone of German war economy and the state organized terror. It is estimated that some five million Polish citizens went through them.[144]

The incomplete list of camp locations with at least one hundred slave labourers, included in alphabetical order: Andrychy, Antoniew-Sikawa, Augustów, Będzin, Białośliwie, Bielsk Podlaski, Bliżyn, Bobrek, Bogumiłów, Boże Dary, Brusy, Burzenin, Chorzów, Dyle, Gidle, Grajewo, Herbertów, Inowrocław, Janów Lubelski, Kacprowice, Katowice, Kazimierza Wielka, Kazimierz Dolny, Klimontów, Koronowo, Kraków-Podgórze, Kraków-Płaszów, Krychów, Lipusz, łysaków, Miechowice, Mikuszowice, Mircze, Mysłowice, Ornontowice, Nowe, Nowy Sącz, Potulice, Rachanie, Słupia, Sokółka, Starachowice, Swiętochłowice, Tarnogród, Wiśnicz Nowy, Wierzchowiska, Włoszczowa, Wola Gozdowska, Żarki, and Zarudzie.[145]

The first German murder camp in occupied Poland was established in late 1941 at Chełmno (renamed Kulmhof) in annexed lands. The new killing method originated from the earlier practise of gassing thousands of unsuspecting hospital patients at Hadamar, Sonnenstein and other euthanasia centres in the Third Reich, known as Action T4.[156] In Chełmno extermination camp, the SS Totenkopfverbände used mobile gas vans to murder mostly Polish Jews imprisoned at the Łódź Ghetto (Litzmannstadt in German). At least 152,000 people were gassed at Chełmno according to postwar verdict by West Germany,[157] although up to 340,000 victims were estimated by the Polish Main Commission for Investigation of German Crimes in Poland (GKBZNwP), a predecessor of the Institute of National Remembrance.[158]

Following the Wannsee Conference of 1942, as part of highly secretive Operation Reinhard in occupied Poland, the German government built three regular killing centres with stationary gas chambers in the General Government. It was the most deadly phase of the Final Solution, based on implementing semi-industrial means of killing and incinerating people. The new facilities included Treblinka extermination camp (set up in July 1942), Bełżec (March 1942), and Sobibor extermination camp (ready in May 1942). Parallel killing facilities were built at Auschwitz-Birkenau within the already existing Auschwitz I in March 1942, at Majdanek later that year.[157][159]

The first Polish political prisoners began to arrive at Auschwitz I in May 1940. By March 1941, 10,900 were imprisoned there. In September 1941, some 200 ill prisoners, most of them Poles, along with 600 Soviet POWs,[160] were killed in the first gassing experiments at Auschwitz. Beginning in 1942, Auschwitz's prisoner population became much more diverse, as Jews and other "undesirables" from all over German-occupied Europe were deported to the camp.[161]

About 960,000 Jews died at Auschwitz amongst its 1.1 million victims, including 438,000 Jews from Hungary and 300,000 Polish Jews, 69,000 French Jews, 60,000 Dutch Jews, and 55,000 Greek Jews.[162][163] The Polish scholar Franciszek Piper, the chief historian of Auschwitz, estimates that 140,000 to 150,000 Poles were brought to that camp between 1940 and 1945, and that 70,000 to 75,000 died there as victims of executions, of medical experiments, and of starvation and disease.[163] There were also hundreds of thousands of victims at concentration camps in Majdanek, Treblinka, and Warsaw.[142]

Film footage taken by the Polish Underground showing the bodies of civilians, including children, murdered by SS troops during the Warsaw Uprising, August 1944

Polish civilians murdered in the Wola massacre. Warsaw, August 1944.

Polish and German historians estimate that during the 1944 Warsaw Uprising up to 200,000 civilians perished. Already in 1944 SS-Gruppenführer Heinz Reinefarth claimed 250,000 dead, which is now considered exaggerated by him for propaganda purposes. Historian Hans von Krannhals claims that at least 10 percent of the victims were killed in mass executions committed by regular German troops,[182] including by Hermann Göring Divisions such as the 1st Infantry Division across Praga, the 2nd Motorized Division in Czerniaków, the 25th Panzergrenadier Division in Marymont as well as the 19th Panzer Division in Praga and Żoliborz districts.[182] The atrocities were closely connected with the planned destruction of Warsaw by Hitler who threatened to "turn it into a lake".[183] The most severe of them took place in the Wola district,[184] where at the beginning of August 1944 tens of thousands of civilians (men, women, and children)[185] were methodically rounded-up and executed by Einsatzkommandos of Sicherheitspolizei operating within the Reinefarth's group of forces under the command of Erich von dem Bach-Zalewski. Executions in the Wola district, referred to as the Wola massacre, also included the killings of both the patients and staff of local hospitals. The victims' bodies were collected and burned under pain of death by the members of the Verbrennungskommando made up of captured Polish men. The carnage was so bad that even the German high command were stunned.[186]

Massacres took place in the areas of Śródmieście (City Centre), Old Town, Marymont, and Ochota districts. In Ochota, civilian killings, rapes, and looting were conducted by the members of Russian SS Sturmbrigade RONA under the command of Bronislav Kaminski and the SS Dirlewanger under the command of Oskar Dirlewanger. Until the end of September 1944, Polish resistance fighters were not considered by the Germans as combatants and were summarily executed when captured. After the fall of the Old Town, during the beginning of September, the remaining 7000 seriously wounded hospital patients were executed or burned alive often with the medical staff who cared for them. Similar atrocities took place later across Czerniaków. Captured insurgents were hanged or otherwise executed after the fall of Powiśle and Mokotów districts as well.[187]

More than 200,000 Poles were killed in the uprising.[86][191] Out of 450,000 surviving civilians, 150,000 were sent to labour camps in Germany,[192][193] and 50,000[192] to 60,000[188] were shipped to death and concentration camps. After the rising had ended, the Germans continued to systematically destroy the city.[194] The city was left in ruins.[195] Neither von dem Bach-Zalewski nor Heinz Reinefarth faced a trial for their actions in the Warsaw Uprising.[196][197]

The role of Soviets is debated by historians. Questions are asked about the Soviet political motives in halting their advance on the city during the uprising, thus allowing for the destruction to continue, and denying the use of their airfields to the Royal Air Force and United States Army Air Forces.[198]

Upon the conclusion of World War II, Poland remained under Soviet military control.[203] Approximately 60,000 soldiers of the Home Army had been arrested by the NKVD. Some 50,000 of them were deported to the gulags and prisons deep in the Soviet Union.[204] After several months of brutal interrogation and torture,[205] 16 leaders of the Polish Underground State were sent to jails in the USSR after a staged trial on trumped-up charges in Moscow. The Soviet Army Northern Group of Forces was stationed in the country until 1956. The persecution of the anti-Nazi resistance members was only a part of the reign of Stalinist terror in Poland. In the period of 1944–56, approximately 300,000 Polish people had been arrested,[206] or up to two million, according to differing accounts.[204] There were 6,000 political death sentences issued, the majority of them carried out.[206] It is estimated that over 20,000 people died in communist prisons including those executed "in the majesty of the law" such as Witold Pilecki or Emil August Fieldorf.[204]