Meanwhile they waited, trying with all their strength to survive just one more day – the slave laborers, the fortunate few still not discovered – and those confined in ghettos such as the teenager who wrote in her diary: “When we look at the fence separating us from the rest of the world, our souls, like birds in a cage, yearn to be free. How I envy the birds that fly to freedom.”
According to the Yad Vashem Holocaust Martyrs' and Heroes' Remembrance Authority in Jerusalem, "[a]ll the serious research" confirms that between five and six million Jews died.[391] Early postwar calculations were 4.2 to 4.5 million from Gerald Reitlinger;[392] 5.1 million from Raul Hilberg; and 5.95 million from Jacob Lestschinsky.[393] In 1986 Lucy S. Dawidowicz used the pre-war census figures to estimate 5.934 million.[394] Yehuda Bauer and Robert Rozett in the Encyclopedia of the Holocaust (1990) estimated 5.59–5.86 million.[395] A 1996 study led by Wolfgang Benz suggested 5.29 to 6.2 million, based on comparing pre- and post-war census records and surviving German documentation on deportations and killings.[391] Martin Gilbert arrived at a minimum of 5.75 million.[396] The figures include over one million children.[397]

Browning wrestles with these and many other related questions in a consistently persuasive and cogent way. He concludes, very sensibly, that it is inconceivable that the Holocaust, unprecedented in history and entailing a massive, counterproductive diversion of resources in wartime, could have taken place without Hitler’s immediate knowledge and approval, although his orders were often, as Browning notes, “vague and inexplicit.” Moreover, Hitler himself was the chief Nazi ideologue of rabid, demented, racialist anti-Semitism, with anti-Semitism at the very center of his worldview and in and of itself a central motivating factor in his foreign and military policies.
Mengele is known as the “Angel of Death,” or sometimes as the “White Angel,” for his coldly cruel demeanor on the ramp. He is associated more closely with this “selection duty” than any other medical officer at Auschwitz, although by most accounts he performed this task no more often than any of his colleagues. The association is partially explained by his postwar notoriety. The pervasive image of Mengele at the ramp in so many survivors' accounts has also to do with the fact that Mengele often appeared “off-duty” in the selection area whenever trainloads of new prisoners arrived at Auschwitz, searching for twins.
Anne Frank and her family fled Germany after the Nazis seized power in 1933 and resettled in the Netherlands, where her father, Otto, had business connections. The Germans occupied Amsterdam in May 1940, and two years later German authorities with help from their Dutch collaborators began rounding up Jews and ultimately deported them to killing centers.
Beginning in late 1941, the Germans began mass transports from the ghettoes in Poland to the concentration camps, starting with those people viewed as the least useful: the sick, old and weak and the very young. The first mass gassings began at the camp of Belzec, near Lublin, on March 17, 1942. Five more mass killing centers were built at camps in occupied Poland, including Chelmno, Sobibor, Treblinka, Majdanek and the largest of all, Auschwitz-Birkenau. From 1942 to 1945, Jews were deported to the camps from all over Europe, including German-controlled territory as well as those countries allied with Germany. The heaviest deportations took place during the summer and fall of 1942, when more than 300,000 people were deported from the Warsaw ghetto alone.
After the end of World War II, surviving archival documents provided a clear record of the Final Solution policies and actions of Nazi Germany. They included the Wannsee Conference Protocol, which documented the co-operation of various German state agencies in the SS-led Holocaust, as well as some 3,000 tons of original German records captured by Allied armies,[23][29] including the Einsatzgruppen reports, which documented the progress of the mobile killing units assigned, among other tasks, to kill Jewish civilians during the attack on the Soviet Union in 1941. The evidential proof which documented the mechanism of the Holocaust was submitted at Nuremberg.[29]
"Dr. Mengele had always been more interested in Tibi. I am not sure why - perhaps because he was the older twin. Mengele made several operations on Tibi. One surgery on his spine left my brother paralyzed. He could not walk anymore. Then they took out his sexual organs. After the fourth operation, I did not see Tibi anymore. I cannot tell you how I felt. It is impossible to put into words how I felt. They had taken away my father, my mother, my two older brothers - and now, my twin ..."
Shortly after Hitler came to power, the Reichstag building, seat of the German parliament, burnt down. Communists were blamed for setting the fire and Hindenburg declared a state of emergency, passing the Reichstag Fire Decree that suspended basic rights like trial by jury. The German Communist Party was suspended and over 4,000 members were detained without trial. The next month, Hitler’s cabinet passed the Enabling Act which allowed him to enact laws without the consent of the parliament for four years, effectively transforming the German government into a de facto Nazi dictatorship.
The German view of the Roma as hereditary criminals and "asocials" was reflected in their classification in the concentration camps, where they were usually counted among the asocials and given black triangles to wear.[420] According to Niewyk and Nicosia, at least 130,000 died out of nearly one million in German-occupied Europe.[415] The United States Holocaust Memorial Museum calculates at least 220,000.[421] Ian Hancock, who specializes in Romani history and culture, argues for between 500,000 and 1,500,000.[422] The treatment of the Roma was not consistent across German-occupied territories. Those in France and the Low Countries were subject to restrictions on movement and some confinement to collection camps, while those in Central and Eastern Europe were sent to concentration camps and murdered by soldiers and execution squads.[423] Before being sent to the camps, the Roma were herded into ghettos, including several hundred into the Warsaw Ghetto.[219] Further east, teams of Einsatzgruppen tracked down Romani encampments and murdered the inhabitants on the spot, leaving no records of the victims.[423] After the Germans occupied Hungary, 1,000 Roma were deported to Auschwitz.[424][x]

Shown in the 1944 photo above, from left to right, are Dr. Josef Mengele, Richard Baer, Karl Hoecker, and Walter Schmidetski. Richard Baer, known as the last Commandant of Auschwitz, was the commander of the main camp; his adjutant was Karl Hoecker. Dr. Josef Mengele was one of 30 SS officers at Auschwitz II, aka Birkenau, who decided who would live and who would die in the gas chambers.

The United States Holocaust Memorial Museum defines the Holocaust as the "systematic, bureaucratic, state-sponsored persecution and murder of six million Jews by the Nazi regime and its collaborators",[29] distinguishing between the Holocaust and the targeting of other groups during "the era of the Holocaust".[30] According to Yad Vashem, Israel's Holocaust memorial, most historians regard the start of the "Holocaust era" as January 1933, when Hitler was named Chancellor of Germany.[31] Other victims of the Holocaust era include those viewed as inferior, including for reasons of race or ethnicity (such as the Roma, ethnic Poles, Russians, and the disabled); and those targeted because of their beliefs or behavior (such as Jehovah's Witnesses, communists, and homosexuals).[30] Hitler came to see the Jews as "uniquely dangerous to Germany", according to Peter Hayes, "and therefore uniquely destined to disappear completely from the Reich and all territories subordinate to it". The persecution and murder of other groups was much less consistent. For example, he writes, the Nazis regarded the Slavs as "sub-human", but their treatment consisted of "enslavement and gradual attrition", while "some Slavs—Slovaks, Croats, Bulgarians, some Ukrainians—[were] allotted a favored place in Hitler's New Order".[20]

The ideology of Nazism brought together elements of antisemitism, racial hygiene, and eugenics, and combined them with pan-Germanism and territorial expansionism with the goal of obtaining more Lebensraum (living space) for the Germanic people.[16] Nazi Germany attempted to obtain this new territory by attacking Poland and the Soviet Union, intending to deport or kill the Jews and Slavs living there, who were considered by the Nazis to be inferior to the Aryan master race.[17]