The Jews killed represented around one third of the world population of Jews, and about two-thirds of European Jewry, based on an estimate of 9.7 million Jews in Europe at the start of the war. Much of the uncertainty stems from the lack of a reliable figure for the number of Jews in Europe in 1939, numerous border changes that make avoiding double-counting of victims difficult, lack of accurate records from the perpetrators, and uncertainty about whether deaths occurring months after liberation, but caused by the persecution, should be counted.
By January 1945 Soviet troops were advancing towards Auschwitz. In desperation to withdraw, the Nazis sent most of the 58,000 remaining prisoners on a death march to Germany, and most prisoners were killed en route. When the Soviet army liberated Auschwitz on January 27, soldiers found only 7,650 barely living prisoners throughout the entire camp complex. In all, approximately one million Jews had been murdered there.
The Warsaw Ghetto Uprising was the largest ghetto revolt. Massive deportations (or Aktions) had been held in the ghetto from July to September 1942, emptying the ghetto of the majority of Jews imprisoned there. When the Germans entered the ghetto again in January 1943 to remove several thousand more, small unorganized groups of Jews attacked them. After four days, the Germans withdrew from the ghetto, having deported far fewer people than they had intended. The Nazis reentered the ghetto on April 19, 1943, the eve of Passover, to evacuate the remaining Jews and close the ghetto. The Jews, using homemade bombs and stolen or bartered weapons, resisted and withstood the Germans for 27 days. They fought from bunkers and sewers and evaded capture until the Germans burned the ghetto building by building. By May 16 the ghetto was in ruins and the uprising crushed.
German military history had been influenced heavily by Carl von Clausewitz, Alfred von Schlieffen and von Moltke the Elder, who were proponents of maneuver, mass, and envelopment. Their concepts were employed in the successful Franco-Prussian War and attempted "knock-out blow" of the Schlieffen Plan. Following the war, these concepts were modified by the Reichswehr. Its Chief of Staff, Hans von Seeckt, moved doctrine away from what he argued was an excessive focus on encirclement towards one based on speed. Speed gives surprise, surprise allows exploitation if decisions can be reached quickly and mobility gives flexibility and speed. Von Seeckt advocated effecting breakthroughs against the enemy's centre when it was more profitable than encirclement or where encirclement was not practical. Under his command a modern update of the doctrinal system called "Bewegungskrieg" and its associated tactical system called " Auftragstaktik" was developed which resulted in the popularly known blitzkrieg effect. He additionally rejected the notion of mass which von Schlieffen and von Moltke had advocated. While reserves had comprised up to four-tenths of German forces in pre-war campaigns, von Seeckt sought the creation of a small, professional (volunteer) military backed by a defense-oriented militia. In modern warfare, he argued, such a force was more capable of offensive action, faster to ready, and less expensive to equip with more modern weapons. The Reichswehr was forced to adopt a small and professional army quite aside from any German plans, for the Treaty of Versailles limited it to 100,000 men.
In early 1942, mass exterminations were moved to two provisional gas chambers (the "red house" and "white house", known as bunkers 1 and 2) in Auschwitz II, while the larger crematoria (II, III, IV, and V) were under construction. Bunker 2 was temporarily reactivated from May to November 1944, when large numbers of Hungarian Jews were gassed. In summer 1944 the combined capacity of the crematoria and outdoor incineration pits was 20,000 bodies per day. A planned sixth facility—crematorium VI—was never built. Prisoners were transported from all over German-occupied Europe by rail, arriving in daily convoys. By July 1942, the SS were conducting "selections". Incoming Jews were segregated; those deemed able to work were sent to the selection officer's right and admitted into the camp, and those deemed unfit for labor were sent to the left and immediately gassed. The group selected to die, about three-quarters of the total,[c] included almost all children, women with small children, the elderly, and all those who appeared on brief and superficial inspection by an SS doctor not to be fit for work.
These techniques were used to great effect in 1939, when the Polish Army was destroyed in a series of encirclement battles. In May 1940 Hitler attacked France, his panzer divisions smashing through slow-moving French formations and cutting off the British Expeditionary Force at Dunkirk. Spectacular success was also achieved during the invasion of the Soviet Union in 1941 and large numbers of Soviet troops were captured.
An inmate's first encounter with the camp, if they were being registered and not sent straight to the gas chamber, would be at the prisoner reception centre, where they were tattooed, shaved, disinfected, and given their striped prison uniform. Built between 1942 and 1944, the center contained a bathhouse, laundry, and 19 gas chambers for delousing clothes. Debórah Dwork and Robert Jan van Pelt write that inmates would then leave this area via a porch that faced the gate with the Arbeit macht frei sign. The prisoner reception center of Auschwitz I became the visitor reception center of the Auschwitz-Birkenau Memorial and Museum.
That month, Himmler ordered the evacuation of all camps, charging camp commanders with "making sure that not a single prisoner from the concentration camps falls alive into the hands of the enemy". Beginning on 17 January, 56,000–58,000 Auschwitz detainees—over 20,000 from Auschwitz I and II, over 30,000 from subcamps, and two-thirds of them Jews—were evacuated under guard, largely on foot, in severe winter conditions, heading west. Around 2,200 were evacuated by rail from two subcamps; fewer than 9,000 were left behind, deemed too sick to move. During the marches, camp staff shot anyone too sick or exhausted to continue, or anyone stopping to urinate or tie a shoelace. SS officers walked behind the marchers killing anyone lagging behind who had not already been shot. Peter Longerich estimates that a quarter of the detainees were thus killed. Those who managed to walk to Wodzisław Śląski and Gliwice were sent on open freight cars, without food, to concentration camps in Germany: Bergen-Belsen, Buchenwald, Dachau, Flossenburg, Gross-Rosen, Mauthausen, Dora-Mittelbau, Ravensbruck, and Sachsenhausen.
Each of the trains carried in excess of a thousand victims. Prisoners had been packed into cattle wagons with no room to sit, no food and two buckets: one for water and another to use as a toilet. The journey could last days on end, with the prisoners not knowing where they were passing through or where they were going. Many victims died during the journey as a result of suffocation, illness or hunger.
In 2005, the historian Karl-Heinz Frieser summarized blitzkrieg as the result of German commanders using the latest technology in the most beneficial way according to traditional military principles and employing "the right units in the right place at the right time". Modern historians now understand blitzkrieg as the combination of the traditional German military principles, methods and doctrines of the 19th century with the military technology of the interwar period. Modern historians use the term casually as a generic description for the style of manoeuvre warfare practised by Germany during the early part of World War II, rather than as an explanation.[b] According to Frieser, in the context of the thinking of Heinz Guderian on mobile combined arms formations, blitzkrieg can be used as a synonym for modern manoeuvre warfare on the operational level.
Before and after the March 1933 Reichstag elections, the Nazis intensified their campaign of violence against opponents. They set up concentration camps for extrajudicial imprisonment. One of the first, at Dachau, opened on 9 March 1933. Initially the camp contained mostly Communists and Social Democrats. Other early prisons were consolidated by mid-1934 into purpose-built camps outside the cities, run exclusively by the SS. The initial purpose of the camps was to serve as a deterrent by terrorizing Germans who did not conform.
Uniquely at Auschwitz, prisoners were tattooed with a serial number, on their left breast for Soviet prisoners of war and on the left arm for civilians. Categories of prisoner were distinguishable by triangular pieces of cloth (German: Winkel) sewn onto on their jackets below their prisoner number. Political prisoners (Schutzhäftlinge or Sch), mostly Poles, had a red triangle, while criminals (Berufsverbrecher or BV) were mostly German and wore green. Asocial prisoners (Asoziale or Aso), which included vagrants, prostitutes and the Roma, wore black. Purple was for Jehovah's Witnesses (Internationale Bibelforscher-Vereinigung or IBV)'s and pink for gay men, who were mostly German. An estimated 5,000–15,000 gay men prosecuted under German Penal Code Section 175 (proscribing sexual acts between men) were detained in concentration camps, of which an unknown number were sent to Auschwitz. Jews wore a yellow badge, the shape of the Star of David, overlaid by a second triangle if they also belonged to a second category. The nationality of the inmate was indicated by a letter stitched onto the cloth. A racial hierarchy existed, with German prisoners at the top. Next were non-Jewish prisoners from other countries. Jewish prisoners were at the bottom.
Schindler was arrested twice on suspicion of black market activities and once for breaking the Nuremberg Laws by kissing a Jewish girl, an action forbidden by the Race and Resettlement Act. The first arrest, in late 1941, led to him being kept overnight. His secretary arranged for his release through Schindler's influential contacts in the Nazi Party. His second arrest, on 29 April 1942, was the result of his kissing a Jewish girl on the cheek at his birthday party at the factory the previous day. He remained in jail five days before his influential Nazi contacts were able to obtain his release. In October 1944, he was arrested again, accused of black marketeering and bribing Göth and others to improve the conditions of the Jewish workers. He was held for most of a week and released. Göth had been arrested on 13 September 1944 for corruption and other abuses of power, and Schindler's arrest was part of the ongoing investigation into Göth's activities. Göth was never convicted on those charges, but was hanged by the Supreme National Tribunal of Poland for war crimes on 13 September 1946.
Entering conquered Soviet territories alongside the Wehrmacht (the German armed forces) were 3,000 men of the Einsatzgruppen (“Deployment Groups”), special mobile killing units. Their task was to murder Jews, Soviet commissars, and Roma in the areas conquered by the army. Alone or with the help of local police, native anti-Semitic populations, and accompanying Axis troops, the Einsatzgruppen would enter a town, round up their victims, herd them to the outskirts of the town, and shoot them. They killed Jews in family units. Just outside Kiev, Ukraine, in the ravine of Babi Yar, an Einsatzgruppe killed 33,771 Jews on September 28–29, 1941. In the Rumbula Forest outside the ghetto in Riga, Latvia, 25,000–28,000 Jews were shot on November 30 and December 8–9. Beginning in the summer of 1941, Einsatzgruppen murdered more than 70,000 Jews at Ponary, outside Vilna (now Vilnius) in Lithuania. They slaughtered 9,000 Jews, half of them children, at the Ninth Fort, adjacent to Kovno (now Kaunas), Lithuania, on October 28.
Schindler grew up in Svitavy, Moravia, and worked in several trades until he joined the Abwehr, the military intelligence service of Nazi Germany, in 1936. He joined the Nazi Party in 1939. Prior to the German occupation of Czechoslovakia in 1938, he collected information on railways and troop movements for the German government. He was arrested for espionage by the Czechoslovak government but was released under the terms of the Munich Agreement in 1938. Schindler continued to collect information for the Nazis, working in Poland in 1939 before the invasion of Poland at the start of World War II. In 1939, Schindler acquired an enamelware factory in Kraków, Poland, which employed at the factory's peak in 1944 about 1,750 workers, of whom 1,000 were Jews. His Abwehr connections helped Schindler protect his Jewish workers from deportation and death in the Nazi concentration camps. As time went on, Schindler had to give Nazi officials ever larger bribes and gifts of luxury items obtainable only on the black market to keep his workers safe.