These experiments were usually exceptionally painful and unneeded. For example, Nazi Dr. Sigmund Rascher subjected some prisoners to high altitude experiments using pressure chambers, while he forced others to undergo freezing experiments so that their reactions to hypothermia could be observed. Still, other prisoners were forced to drink saltwater during efforts to determine its drinkability.
In January 1941, Dachau was designated a Class I camp and Buchenwald became a Class II camp; Mauthausen and Gusen in Austria were the only Class III camps in the Nazi system. The Class I designation meant that treatment of the inmates was less harsh and that prisoners had a better chance of being released. Dachau was the best of the Nazis camps, as far as the treatment of the prisoners was concerned.

After WWII had ended, photographs of the Holocaust stunned the public. Newspapers in the United States had reported on the oppression of the Jews in Germany during the war. In 1942, many newspapers were writing details of the Holocaust, but these stories were short and were not widely read. In 1943, after sources had confirmed the killings of at least two million Jews in concentration camps across Europe a Gallup poll found that less than half of Americans believed these reports to be true; 28% thought they were “just a rumor”. The reports were unconfirmed and sometimes denied by the United States government.

Then as a last straw the Allies bombed the electric plant that pumped our water. Loads of food were unable to reach the camp because of the Allied fighters. Then things really got out of hand. During the last six weeks I have been helpless. I did not even have sufficient staff to bury the dead, let alone segregate the sick ... I tried to get medicines and food for the prisoners and I failed. I was swamped. I may have been hated, but I was doing my duty.
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]
The first Jewish prisoners came as known political opponents of the Nazis. At Dachau, as elsewhere, they received even worse treatment than the other prisoners. Gradually, more and more groups were arrested and brought to Dachau, Jehovah’s Witness, Gypsies, who like the Jews were classified as racially inferior, Clergymen who resisted the Nazi coercion of the churches and Homosexuals and many others who had been denounced for making critical remarks against the Nazi regime.
Throughout the Middle Ages in Europe, Jews were subjected to antisemitism based on Christian theology, which blamed them for killing Jesus. Even after the Reformation, Catholicism and Lutheranism continued to persecute Jews, accusing them of blood libels and subjecting them to pogroms and expulsions.[60][61] The second half of the 19th century saw the emergence in the German empire and Austria-Hungary of the völkisch movement, which was developed by such thinkers as Houston Stewart Chamberlain and Paul de Lagarde. The movement embraced a pseudo-scientific racism that viewed Jews as a race whose members were locked in mortal combat with the Aryan race for world domination.[62] These ideas became commonplace throughout Germany,[63] with the professional classes adopting an ideology that did not see humans as racial equals with equal hereditary value.[64] Although the völkisch parties had support in elections at first, by 1914 they were no longer influential. This did not mean that antisemitism had disappeared; instead it was incorporated into the platforms of several mainstream political parties.[63]
Most of the Jewish ghettos of General Government were liquidated in 1942–1943, and their populations shipped to the camps for extermination.[349][350][t] About 42,000 Jews were shot during the Operation Harvest Festival on 3–4 November 1943.[351] At the same time, rail shipments arrived regularly from western and southern Europe at the extermination camps.[352] Few Jews were shipped from the occupied Soviet territories to the camps: the killing of Jews in this zone was mostly left in the hands of the SS, aided by locally recruited auxiliaries.[353][u]

Though at the time of liberation the death rate had peaked at 200 per day, after the liberation by U.S. forces the rate eventually fell to between 50 and 80 deaths per day. In addition to the direct abuse of the SS and the harsh conditions, people died from typhus epidemics and starvation. The number of inmates had peaked in 1944 with transports from evacuated camps in the east (such as Auschwitz), and the resulting overcrowding led to an increase in the death rate.[47]
By July 1944, Germany was losing the war; the SS began closing down the easternmost concentration camps and deporting the remaining prisoners westward. Many were killed in Auschwitz and the Gross-Rosen concentration camp. Schindler convinced SS-Hauptsturmführer Amon Göth, commandant of the nearby Kraków-Płaszów concentration camp, to allow him to move his factory to Brněnec in the Protectorate of Bohemia and Moravia, thus sparing his workers from almost certain death in the gas chambers. Using names provided by Jewish Ghetto Police officer Marcel Goldberg, Göth's secretary Mietek Pemper compiled and typed the list of 1,200 Jews who travelled to Brünnlitz in October 1944. Schindler continued to bribe SS officials to prevent the execution of his workers until the end of World War II in Europe in May 1945, by which time he had spent his entire fortune on bribes and black market purchases of supplies for his workers.
Methods of mass murder evolved at local levels as well as being decreed from Nazi high command. Killing squads rounded up and shot entire Jewish communities. Over two days in Kiev, 33,771 Jews were shot. The murder of Jews rapidly escalated, in part because local Nazi leaders didn’t have enough room to place them in the ghettos. By the end of the year, plans to implement the systematic slaughter of Jews by using gas in mobile trucks and gas chambers were well underway.
One of the most remarkable humanitarian acts performed by Oskar and Emilie Schindler involved the case of 120 Jewish male prisoners from Goleszow, a sub-camp of Auschwitz. The men had been working there in a quarry plant that belonged to the SS-operated company “German Earth and Stone Works.”  With the approach of the Russian front in January 1945, they were evacuated from Goleszow and transported westward in sealed cattle-wagons, without food or water. At the end of a seven-day grueling journey in the dead of winter, the SS guards finally stationed the two sealed cattle-cars with their human cargo at the gates of Brunnlitz. Emilie Schindler was just in time to stop the SS camp commandant from sending the train back. Schindler, who had rushed back to the camp from some food-procuring errand outside, barely managed to convince the commandant that he desperately needed the people who were locked in the train for work.
Finland was pressured in 1942 to hand over its 150–200 non-Finnish Jews to Germany. After opposition from the government and public, eight non-Finnish Jews were deported in late 1942; only one survived the war.[173] Japan had little antisemitism in its society and did not persecute Jews in most of the territories it controlled. Jews in Shanghai were confined, but despite German pressure they were not killed.[174]
The Nuremberg Laws, issued on Sept. 15, 1935, was designed to exclude Jews from public life. The Nuremberg Laws stripped German Jews of their citizenship and prohibited marriages and extramarital sex between Jews and Gentiles. These measures set the legal precedent for anti-Jewish legislation that followed. Nazis issued numerous anti-Jewish laws over the next several years. Jews were banned from public parks, fired from civil service jobs, and forced to register their property. Other laws barred Jewish doctors from treating anyone other than Jewish patients, expelled Jewish children from public schools, and placed severe travel restrictions on Jews.

The Nazis regarded the Slavs as subhuman, or Untermenschen.[426] In a secret memorandum dated 25 May 1940, Himmler stated that it was in German interests to foster divisions between the ethnic groups in the East. He wanted to restrict non-Germans in the conquered territories to schools that would only teach them how to write their own name, count up to 500, and obey Germans.[427][y] In November 1939 German planners called for "the complete destruction" of all Poles[430] and resettlement of the land by German colonists.[431] The Polish political leadership was the target of a campaign of murder (Intelligenzaktion and AB-Aktion).[432] Between 1.8 and 1.9 million non-Jewish Polish citizens perished at German hands during the course of the war; about four-fifths were ethnic Poles and the rest Ukrainians and Belarusians.[410] At least 200,000 died in concentration camps, around 146,000 in Auschwitz. Others died in massacres or in uprisings such as the Warsaw Uprising, where 120,000–200,000 were killed.[433] During the occupation, the Germans adopted a policy of restricting food and medical services, as well as degrading sanitation and public hygiene.[434] The death rate rose from 13 per 1000 before the war to 18 per 1000 during the war.[435] Around 6 million of World War II victims were Polish citizens; half the death toll were Jews.[436] Over the course of the war Poland lost 20 percent of its pre-war population.[436] Over 90 percent of the death toll came through non-military losses, through various deliberate actions by Germany and the Soviet Union.[433] Polish children were also kidnapped by Germans to be "Germanized", with perhaps as many as 200,000 children stolen from their families.[437]
These dead victims of the Germans were removed from the Lambach concentration camp in Austria, on May 6, 1945, by German soldiers under orders of U.S. Army troops. As soon as all the bodies were removed from the camp, the Germans buried them. This camp originally held 18,000 people, each building housing 1,600. There were no beds or sanitary facilities whatsoever, and 40 to 50 prisoners died each day. #

That February 28 decree had been used by the 50,000 brown-shirted SA storm troopers and black-coated SS men sworn in as auxiliary police to justify mass arrests of political opponents during Hitler's seizure of power. There were so many people in custody in the spring of 1933 that Germany's conventional prisons were quickly swamped. As a result, 'wild' prison camps sprang up like mushrooms.
Until late 1944 conditions were generally better than in other concentration camps. Marika Frank Abrams, a Jewish woman from Hungary, was transferred from Auschwitz in 1944. Years later she recalled her arrival at Belsen: "... We were each given two blankets and a dish. There was running water and latrines. We were given food that was edible and didn't have to stand for hours to be counted. The conditions were so superior to Auschwitz we felt we were practically in a sanitarium." /3
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.
There were no gas chambers at Bergen-Belsen, since the mass killings took place in the camps further east. Nevertheless, current estimates put the number of deaths at Belsen at more than 50,000 Jews, Czechs, Poles, anti-Nazi Christians, homosexuals, and Roma and Sinti (Gypsies).[7] Among them was Czech painter and writer Josef Čapek (estimated to be in April 1945). He had coined the word robot, popularised by his brother Karel Čapek.