Because they refused to pledge allegiance to the Nazi party or serve in the military, Jehovah's Witnesses were sent to concentration camps, where they were identified by purple triangles and given the option of renouncing their faith and submitting to the state's authority.[447] The United States Holocaust Memorial Museum estimates that between 2,700 and 3,300 were sent to the camps, where 1,400 died;[411] in The Holocaust Encyclopedia (2001), Sybil Milton estimates that 10,000 were sent and 2,500 died.[412] According to German historian Detlef Garbe, "no other religious movement resisted the pressure to conform to National Socialism with comparable unanimity and steadfastness."[448]
Historians increasingly view the Holocaust as a pan-European phenomenon, or a series of holocausts impossible to conduct without the help of local collaborators.[47] Over 200,000 people are estimated to have been Holocaust perpetrators;[48] without them, the Germans would not have been able to extend the Holocaust across most of Europe.[49] Some Christian churches tried to defend the Jews by declaring that converted Jews were "part of the flock," according to Saul Friedländer, "but even then only up to a point". Otherwise, Friedländer writes, "[n]ot one social group, not one religious community, not one scholarly institution or professional association in Germany and throughout Europe declared its solidarity with the Jews."[50]
As discrimination against Jews increased, German law required a legal definition of a Jew and an Aryan. Promulgated at the annual Nazi Party rally in Nürnberg on September 15, 1935, the Nürnberg Laws—the Law for the Protection of German Blood and German Honour and the Law of the Reich Citizen—became the centrepiece of anti-Jewish legislation and a precedent for defining and categorizing Jews in all German-controlled lands. Marriage and sexual relations between Jews and citizens of “German or kindred blood” were prohibited. Only “racial” Germans were entitled to civil and political rights. Jews were reduced to subjects of the state. The Nürnberg Laws formally divided Germans and Jews, yet neither the word German nor the word Jew was defined. That task was left to the bureaucracy. Two basic categories were established in November: Jews, those with at least three Jewish grandparents; and Mischlinge (“mongrels,” or “mixed breeds”), people with one or two Jewish grandparents. Thus, the definition of a Jew was primarily based not on the identity an individual affirmed or the religion he or she practiced but on his or her ancestry. Categorization was the first stage of destruction.
In a blitzkrieg, tanks and troop-transport vehicles were concentrated, and massive attacks by dive bombers were conducted on enemy front-line positions. When these forces had broken through, they continued deep into enemy territory, encircling and cutting off the enemy. The techniques were first developed by the German army late in World War I in an effort to overcome static trench warfare, but the Germans lacked the mobility to succeed. Between the wars, armored tactics were further developed by Basil Liddell Hart and J. F. C. Fuller in Britain, Charles de Gaulle in France, and Heinz Guderian in Germany. Made chief of German mobile troops in 1938, Guderian led the drive across France in 1940.
During the Holocaust, concentration camp prisoners received tattoos only at one location, Auschwitz. Incoming prisoners were assigned a camp serial number which was sewn to their prison uniforms. Only those prisoners selected for work were issued serial numbers; those prisoners sent directly to the gas chambers were not registered and received no tattoos.
Directive control was a fast and flexible method of command. Rather than receiving an explicit order, a commander would be told of his superior's intent and the role which his unit was to fill in this concept. The exact method of execution was then a matter for the low-level commander to determine as best fit the situation. Staff burden was reduced at the top and spread among commands more knowledgeable about their own situation. In addition, the encouragement of initiative at all levels aided implementation. As a result, significant decisions could be effected quickly and either verbally or with written orders a few pages in length.
Although the Germans destroyed parts of the camps before abandoning them in 1945, much of Auschwitz I and Auschwitz II (Birkenau) remained intact and were later converted into a museum and memorial. The site has been threatened by increased industrial activity in Oświęcim. In 1996, however, the Polish government joined with other organizations in a large-scale effort to ensure its preservation. Originally named Auschwitz Concentration Camp, the memorial was designated a UNESCO World Heritage site in 1979. It was renamed “Auschwitz-Birkenau. The Nazi German Concentration and Extermination Camp (1940–1945)” in 2007.
The early 1950s literature transformed blitzkrieg into a historical military doctrine, which carried the signature of Liddell Hart and Guderian. The main evidence of Liddell Hart's deceit and "tendentious" report of history can be found in his letters to Erich von Manstein, Heinz Guderian and the relatives and associates of Erwin Rommel. Liddell Hart, in letters to Guderian, "imposed his own fabricated version of blitzkrieg on the latter and compelled him to proclaim it as original formula".[145][146] Kenneth Macksey found Liddell Hart's original letters to Guderian in the General's papers, requesting that Guderian give him credit for "impressing him" with his ideas of armoured warfare. When Liddell Hart was questioned about this in 1968 and the discrepancy between the English and German editions of Guderian's memoirs, "he gave a conveniently unhelpful though strictly truthful reply. ('There is nothing about the matter in my file of correspondence with Guderian himself except...that I thanked him...for what he said in that additional paragraph'.)".[147]

The brick barracks were constructed in the autumn of 1941. The Germans originally intended the barracks to house 40 prisoners, but very often more than 700 would be placed in each of them. The total number of prisoners to each barrack depended on the number of transports arriving. The prisoners slept in 60 spaces, with three bunks in each space. Prisoners slept on straw spread over the wooden bunks. The barracks had earth floors and few sanitary facilities.
Under Laks' more positive leadership, the orchestra began to increase in size again.  His efforts won his musicians easier work assignments and a dispensation not to play outdoors in bad weather.  By the end of 1943, there were about forty members, including many Jews, from France, Germany, Poland, the Netherlands and Greece.  They included Henry Meyer, Louis Bannet, and Jacques Stroumsa.

On January 20, 1942, several top officials of the German government met to officially coordinate the military and civilian administrative branches of the Nazi system to organize a system of mass murder of the Jews. This meeting, called the Wannsee Conference, "marked the beinning of the full-scale, comprehensive extermination operation [of the Jews] and laid the foundations for its organization, which started immediately after the conference ended" (Yahil, The Holocaust, p. 318).

In 1983, French scholar George Wellers was one of the first to use German data on deportations; he arrived at a figure of 1,471,595 deaths, including 1.35 million Jews and 86,675 Poles.[190] A larger study in the late 1980s by Franciszek Piper, published by Yad Vashem in 1991,[191] used timetables of train arrivals combined with deportation records to calculate that, of the 1.3 million deported to the camp, 1,082,000 died there between 1940 and 1945, a figure (rounded up to 1.1 million) that he regarded as a minimum[192] and that came to be widely accepted.[e]
 In October 1944, after the SS transferred the Emalia Jews to Plaszow, Schindler sought and obtained authorization to relocate his plant to Brünnlitz (Brnenec) in Moravia, and reopen it exclusively as an armaments factory. One of his assistants drew several versions of a list of up to 1,200 Jewish prisoners needed to work in the new factory. These lists came to be known collectively as “Schindler's List.” Schindler met the specifications required by the SS to classify Brünnlitz as a subcamp of Gross-Rosen concentration camp and thereby facilitated the survival of around 800 Jewish men whom the SS deported from Plaszow via Gross-Rosen to Brünnlitz and between 300 and 400 Jewish women from Plaszow via Auschwitz.
When the wagons were forced open, a terrible sight was revealed. The Schindlers took charge of the 107 survivors, with terrible frostbite and frightfully emaciated, arranged for medical treatment and gradually nourished them back to life. Schindler also stood up to the Nazi Commandant who wanted to incinerate the corpses that were found frozen in the boxcars, and  arranged for their burial with full Jewish religious rites in a plot of land near the Catholic cemetery, which he had especially bought for that purpose.
The Germans invaded the Netherlands, Luxembourg, Belgium, and France in May 1940. In the Netherlands, the Germans installed Arthur Seyss-Inquart as Reichskommissar, who quickly began to persecute the approximately 140,000 Dutch Jews. Jews were forced out of their jobs and had to register with the government. Non-Jewish Dutch citizens protested these measures, and in February 1941 they staged a strike that was quickly crushed.[161] After Belgium's surrender at the end of May 1940, it was ruled by a German military governor, Alexander von Falkenhausen, who enacted anti-Jewish measures against the country's 90,000 Jews, many of whom were refugees from Germany or Eastern Europe.[162]

On 1 August 1940, Governor-General Hans Frank issued a decree requiring all Kraków Jews to leave the city within two weeks. Only those who had jobs directly related to the German war effort would be allowed to stay. Of the 60,000 to 80,000 Jews then living in the city, only 15,000 remained by March 1941. These Jews were then forced to leave their traditional neighbourhood of Kazimierz and relocate to the walled Kraków Ghetto, established in the industrial Podgórze district.[41][42] Schindler's workers travelled on foot to and from the ghetto each day to their jobs at the factory.[43] Enlargements to the facility in the four years Schindler was in charge included the addition of an outpatient clinic, co-op, kitchen, and dining room for the workers, in addition to expansion of the factory and its related office space.[44]