The first experimental gassing took place in September 1941, when Lagerführer Karl Fritzsch, at the instruction of Rudolf Höss, killed a group of Soviet prisoners of war by throwing Zyklon B crystals into their basement cell in block 11 of Auschwitz I. A second group of 600 Soviet prisoners of war and around 250 sick Polish prisoners was gassed on 3–5 September.[29] The morgue was later converted to a gas chamber able to hold at least 700–800 people.[30] Zyklon B was dropped into the room through slits in the ceiling.[28] In the view of Filip Müller, one of the Sonderkommando who worked in crematorium I, tens of thousands of Jews were killed there from France, Holland, Slovakia, Upper Silesia, Yugoslavia, and from the Theresienstadt, Ciechanow, and Grodno ghettos.[31] The last inmates to be gassed in Auschwitz I, in December 1942, were 300–400 members of the Auschwitz II Sonderkommando, who had been forced to dig up that camp's mass graves, thought to hold 100,000 corpses, and burn the remains.[32]
In nearly every country overrun by the Nazis, the Jews were forced to wear badges marking them as Jews, they were rounded up into ghettos or concentration camps and then gradually transported to the killing centers. The death camps were essentially factories for murdering Jews. The Germans shipped thousands of Jews to them each day. Within a few hours of their arrival, the Jews had been stripped of their possessions and valuables, gassed to death, and their bodies burned in specially designed crematoriums. Approximately 3.5 million Jews were murdered in these death camps.
Birkenau was the largest camp in the Auschwitz complex. It became primarily a centre for the mass murder of Jews brought there for extermination, and of Roma and Sinti prisoners during its final period. Sick prisoners and those selected for death from the whole Auschwitz complex – and, to a smaller extent, from other camps – were also gathered and systematically killed here. It ultimately became a place for the concentration of prisoners before they were transferred inside the Third Reich to work for German industry. Most of the victims of the Auschwitz complex, probably about 90%, were killed in the Birkenau camp.

Uniquely at Auschwitz, prisoners were tattooed with a serial number, on their left breast for Soviet prisoners of war[97] and on the left arm for civilians.[98] 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.[99] 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.[100] 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.[101]
The first “bunker,” with two sealed rooms, operated from January 1942 to the end of that year. The second, with four air tight rooms, became redundant in the spring of 1943, but remained standing and was used again in the autumn of 1944 when extra “capacity” was needed for the murder of Hungarian Jews and the liquidation of the ghettos. The second measured about 1.134 square feet. The victims murdered in the “bunkers” were first obliged to undress in temporary wooden barracks erected nearby. Their bodies were taken out of the gas chambers and pushed to pits where they were burned in the open.
In September 1939, the German army occupied the western half of Poland. German police soon forced tens of thousands of Polish Jews from their homes and into ghettoes, giving their confiscated properties to ethnic Germans (non-Jews outside Germany who identified as German), Germans from the Reich or Polish gentiles. Surrounded by high walls and barbed wire, the Jewish ghettoes in Poland functioned like captive city-states, governed by Jewish Councils. In addition to widespread unemployment, poverty and hunger, overpopulation made the ghettoes breeding grounds for disease such as typhus.

France had approximately 300,000 Jews, divided between the German-occupied north and the unoccupied collaborationist southern areas under the Vichy regime. The occupied regions were under the control of a military governor, and there, anti-Jewish measures were not enacted as quickly as they were in the Vichy-controlled areas.[163] In July 1940, the Jews in the parts of Alsace-Lorraine that had been annexed to Germany were expelled into Vichy France.[164] Vichy France's government implemented anti-Jewish measures in French Algeria and the two French Protectorates of Tunisia and Morocco.[165] Tunisia had 85,000 Jews when the Germans and Italians arrived in November 1942. An estimated 5,000 Jews were subjected to forced labor.[166]
A parallel system operated later at Birkenau in 1942-43, except that for the majority the 'showers' proved to be gas chambers. Only about 10 percent of Jewish transports were registered, disinfected, shaven and showered in the 'central sauna' before being assigned barracks. In May 1944, a spur line was built right into the camp to accelerate and simplify the handling of the tens of thousands of Hungarian and other Jews deported in the spring and summer of 1944.

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.
Sunday was not a work day, but prisoners were required to clean the barracks and take their weekly shower,[115] and were allowed to write (in German) to their families, although the SS censored the outgoing mail. Inmates who did not speak German would trade some of their bread for help composing their letters.[116] Observant Jews tried to keep track of the Hebrew calendar and Jewish holidays, including Shabbat, and the weekly Torah portion. No watches, calendars, or clocks were permitted in the camp. Jewish calendars were rare among prisoners; being in possession of one was dangerous. Only two Jewish calendars made in Auschwitz survived to the end of the war. Prisoners kept track of the days in other ways, such as obtaining information from newcomers.[117]
After this night, the German government supported dozens of laws and decrees that took away Jews property and livelihood. By the end of the year, Jews were prohibited from attending school. One billion reichsmarks of Jewish property was seized as collective punishment against the nation’s Jews for the murder of von Rath. Those able to flee the country did. In the year after Kristallnact, more than 100,000 Jews left Germany as the situation deteriorated.

The mass killings of Jews in the occupied Soviet territories were assigned to four SS formations called Einsatzgruppen ("task groups"), which were under Heydrich's overall command. Similar formations had been used to a limited extent in Poland in 1939, but the ones operating in the Soviet territories were much larger.[242] The Einsatzgruppen's commanders were ordinary citizens: the great majority were professionals and most were intellectuals.[243] By the winter of 1941–1942, the four Einsatzgruppen and their helpers had killed almost 500,000 people.[244] The largest massacre of Jews by the mobile killing squads in the Soviet Union was at a ravine called Babi Yar outside Kiev,[245] where 33,771 Jews were killed in a single operation on 29–30 September 1941.[246][n] A mixture of SS and Security Police, assisted by Ukrainian police, carried out the killings.[248] Although they did not actively participate in the killings, men of the German 6th Army helped round up the Jews of Kiev and transport them to be shot.[249] By the end of the war, around two million are thought to have been victims of the Einsatzgruppen and their helpers in the local population and the German Army. Of those, about 1.3 million were Jews and up to a quarter of a million Roma.[250]
March 11, 1946 - Former Auschwitz Kommandant Höss, posing as a farm worker, is arrested by the British. He testifies at Nuremberg, then is later tried in Warsaw, found guilty and hanged at Auschwitz, April 16, 1947, near Crematory I. "History will mark me as the greatest mass murderer of all time," Höss writes while in prison, along with his memoirs about Auschwitz.
The first 'bunker', with two sealed rooms, operated from January 1942 to the end of that year. The second, with four air tight rooms, became redundant in the spring of 1943, but remained standing and was used again in the autumn of 1944 when extra 'capacity' was needed for the murder of Hungarian Jews and the liquidation of the ghettos. The second measured about 1.134 square feet. The victims murdered in the 'bunkers' were first obliged to undress in temporary wooden barracks erected nearby. Their bodies were taken out of the gas chambers and pushed to pits where they were burned in the open. Between January 1942 and March 1943, 175,000 Jews were gassed to death here, of whom 105,000 were killed from January to March 1943.
Auschwitz-Birkenau was the largest Nazi extermination and concentration camp, located in the Polish town of Oswiecim, 37 miles west of Cracow. One sixth of all Jews murdered by the Nazis were gassed at Auschwitz. In April 1940 SS chief Heinrich Himmler ordered the establishment of a new concentration camp in Oswiecim, a town located within the portion of Poland that was annexed to Germany at the beginning of World War II. The first Polish political prisoners arrived in Auschwitz in June 1940, and by March 1941 there were 10,900 prisoners, the majority of whom were Polish. Auschwitz soon became known as the most brutal of the Nazi concentration camps.
The Auschwitz I main camp was a place of extermination, effected mainly by depriving people of elementary living conditions. It was also a centre for immediate extermination. Here were located the offices of the camp’s administration, the local garrison commander and the commandant of Auschwitz I, the seat of the central offices of the political department, and the prisoner labour department. Here too were the main supply stores, workshops and Schutzstaffel (SS) companies. Work in these administrative and economic units and companies was the main form of forced labour for the inmates in this camp.

The Holocaust began in 1933 when Adolf Hitler came to power in Germany and ended in 1945 when the Nazis were defeated by the Allied powers. The term Holocaust is derived from the Greek word holokauston, which means sacrifice by fire. It refers to the Nazi persecution and planned slaughter of the Jewish people and others considered inferior to "true" Germans. The Hebrew word Shoah, which means devastation, ruin or waste, also refers to this genocide.

Recognising that battlefield conditions changed rapidly and that orders often became overtaken by events, the German army encouraged its commanders to make decisions without waiting for orders from above, thus allowing them to take advantage of fleeting opportunities as they arose. Above all else, this doctrine created aggressive and flexible leaders.

For the first time, camps were created specifically for Jews. Their conditions were far worse than other camps. The implicit intention was that the inmates would die there. Increasing numbers of Jews in Poland were relocated in ghettos. Non-Jewish Poles were also deported from their farms and villages to make room for ‘pure’ ethnic Germans to populate the new territory.
In Birkenau, which was built anew on the site of a displaced village, only a small number of historic buildings have survived. Due to the method used in constructing those buildings, planned as temporary structures and erected in a hurry using demolition materials, the natural degradation processes have been accelerating. All efforts are nevertheless being taken to preserve them, strengthen their original fabric and protect them from decay.

The Third Reich first used concentration camps as places of unlawful incarceration of political opponents and other "enemies of the state". Large numbers of Jews were not sent there until after Kristallnacht in November 1938.[182] Although death rates were high, the camps were not designed as killing centers.[183] After war broke out in 1939, new camps were established, some outside Germany in occupied Europe.[184] In January 1945, the SS reports had over 700,000 prisoners in their control, of which close to half had died by the end of May 1945 according to most historians.[185] Most wartime prisoners of the camps were not Germans but belonged to countries under German occupation.[186]
His tasks for the Abwehr included collecting information on railways, military installations, and troop movements, as well as recruiting other spies within Czechoslovakia, in advance of a planned invasion of the country by Nazi Germany.[9] He was arrested by the Czech government for espionage on 18 July 1938 and immediately imprisoned, but was released as a political prisoner under the terms of the Munich Agreement, the instrument under which the Czech Sudetenland was annexed into Germany on 1 October.[10][11] Schindler applied for membership in the Nazi Party on 1 November and was accepted the following year.[12]