After Germany invaded Poland in September 1939, sparking World War II, the Germans converted Auschwitz I from an army barracks to hold Polish political prisoners.[3] The first prisoners, German criminals brought to the camp as functionaries, arrived in May 1940,[4] and the first gassing of prisoners took place in block 11 of Auschwitz I in September 1941. Auschwitz II–Birkenau went on to become a major site of the Nazis' Final Solution to the Jewish Question. From early 1942 until late 1944, transport trains delivered Jews from all over German-occupied Europe to the camp's gas chambers. Of the estimated 1.3 million people sent to Auschwitz, at least 1.1 million died,[5] around 90 percent of them Jews.[6] Approximately one in six Jews killed in the Holocaust died at the camp.[7] Others deported to Auschwitz included 150,000 non-Jewish Poles, 23,000 Roma, 15,000 Soviet prisoners of war, 400 Jehovah's Witnesses, tens of thousands of others of diverse nationalities, and an unknown number of gay men. Many of those not killed in the gas chambers died because of starvation, forced labor, infectious diseases, individual executions, and medical experiments.
took unlimited advantage of their power.  They could beat us, torture us, even kill us without having to answer to anyone. Those who could not take this treatment threw themselves into the electric fence.  These suicides built up the rage of our tormentors even more.  One day, when the number of musicians who had killed themselves the night before was higher than usual, they called us all together and said 'sons of whores, I warn you all, if you keep leaping into the electric wire, I will kill you all like dogs'.
Blitzkrieg also has had some influence on subsequent militaries and doctrines. The Israel Defense Forces may have been influenced by blitzkrieg in creating a military of flexible armored spearheads and close air support. The 1990's United States theorists of " Shock and awe" claim blitzkrieg as a subset of strategies which they term "rapid dominance".
Meanwhile, beginning in the fall of 1939, Nazi officials selected around 70,000 Germans institutionalized for mental illness or disabilities to be gassed to death in the so-called Euthanasia Program. After prominent German religious leaders protested, Hitler put an end to the program in August 1941, though killings of the disabled continued in secrecy, and by 1945 some 275,000 people deemed handicapped from all over Europe had been killed. In hindsight, it seems clear that the Euthanasia Program functioned as a pilot for the Holocaust.
In the last months of Hitler’s Reich, as the German armies retreated, the Nazis began marching the prisoners still alive in the concentration camps to the territory they still controlled. The Germans forced the starving and sick Jews to walk hundreds of miles. Most died or were shot along the way. About a quarter of a million Jews died on the death marches.
Nevertheless, despite the lack of access to clean water, soap and a change of clothes, many prisoners continued to go through the motions of washing each morning. This was because, even though it was not possible to carry out the activities of a normal life, it was extremely important to preserve the ‘spirit’ of life, not to give up. This can be seen so vividly in the writings of Primo Levi, a survivor of Auschwitz, who went on to become a distinguished writer,
Auschwitz, perhaps the most notorious and lethal of the concentration camps, was actually three camps in one: a prison camp (Auschwitz I), an extermination camp (Auschwitz II–Birkenau), and a slave labour camp (Auschwitz III–Buna-Monowitz). Upon arrival, Jewish prisoners faced what was called a Selektion. A German doctor presided over the selection of pregnant women, young children, the elderly, handicapped, sick, and infirm for immediate death in the gas chambers. As necessary, the Germans selected able-bodied prisoners for forced labour in the factories adjacent to Auschwitz, where one German company, IG Farben, invested 700 million Reichsmarks in 1942 alone to take advantage of forced labour, a capital investment. The conglomerate presumed that slave labour would be a permanent part of the German economy. Deprived of adequate food, shelter, clothing, and medical care, these prisoners were literally worked to death. Periodically, they would face another Selektion. The Nazis would transfer those unable to work to the gas chambers of Birkenau.
The concept of blitzkrieg was formed by Prussian military tactics of the early 19th century, which recognized that victory could come only through forceful and swift action because of Prussia’s relatively limited economic resources. It had its origins with the Schwerpunktprinzip (“concentration principle”) proposed by Carl von Clausewitz in his seminal work On War (1832). Having studied generals who predated Napoleon, Clausewitz found that commanders of various armies had dispersed their forces without focused reasoning, which resulted in those forces’ being used inefficiently. So as to eliminate that wasteful use of manpower, he advocated for a concentration of force against an enemy. All employment of force should have an effective concentration in a single moment, with a single action, Clausewitz argued. Clausewitz called that concentration the Schwerpunkt (“centre of gravity”) where it was most dense, identifying it as the effective target for attack.

Irena Adamowicz Gino Bartali Archbishop Damaskinos Odoardo Focherini Francis Foley Helen of Greece and Denmark Princess Alice of Battenberg Marianne Golz Jane Haining Feng-Shan Ho Wilm Hosenfeld Constantin Karadja Jan Karski Valdemar Langlet Carl Lutz Aristides de Sousa Mendes Tadeusz Pankiewicz Giorgio Perlasca Marion Pritchard Ángel Sanz Briz Oskar Schindler Anton Schmid Irena Sendler Klymentiy Sheptytsky Ona Šimaitė Henryk Sławik Tina Strobos Chiune Sugihara Casper ten Boom Corrie ten Boom Johan van Hulst Raimondo Viale Raoul Wallenberg Johan Hendrik Weidner Rudolf Weigl Jan Zwartendijk