In May 14, 1940, the Netherlands surrendered to Germany after the bombing of Rotterdam, having being invaded just five days earlier. The following month, Anne turned 10. The restrictions and persecution the Franks had faced in Germany were brought to their new home. Otto transferred control of his businesses to trusted colleagues to make the business appear Aryan-owned and to avoid having to register it with the German authorities. The family had to register as Jews with the German authorities in January 1942 and all Dutch Jews were ordered to Amsterdam.
The unified armed forces of Germany from 1935 to 1945 were called the Wehrmacht (defence force). This included the Heer (army), Kriegsmarine (navy), and the Luftwaffe (air force). From 2 August 1934, members of the armed forces were required to pledge an oath of unconditional obedience to Hitler personally. In contrast to the previous oath, which required allegiance to the constitution of the country and its lawful establishments, this new oath required members of the military to obey Hitler even if they were being ordered to do something illegal. Hitler decreed that the army would have to tolerate and even offer logistical support to the Einsatzgruppen—the mobile death squads responsible for millions of deaths in Eastern Europe—when it was tactically possible to do so. Wehrmacht troops also participated directly in the Holocaust by shooting civilians or committing genocide under the guise of anti-partisan operations. The party line was that the Jews were the instigators of the partisan struggle and therefore needed to be eliminated. On 8 July 1941, Heydrich announced that all Jews in the eastern conquered territories were to be regarded as partisans and gave the order for all male Jews between the ages of 15 and 45 to be shot. By August this was extended to include the entire Jewish population.
Despite the horrible conditions, prisoners in Auschwitz managed to resist the Nazis, including some instances of escape and armed resistance. In October 1944, members of the Sonderkommando, who worked in the crematoria, succeeded in killing several SS men and destroying one gas chamber. All of the rebels died, leaving behind diaries that provided authentic documentation of the atrocities committed at Auschwitz.
In the Soviet Union by 1922 there were 23 concentration camps for the incarceration of persons accused of political offenses as well as criminal offenses. Many corrective labour camps were established in northern Russia and Siberia, especially during the First Five-Year Plan, 1928–32, when millions of rich peasants were driven from their farms under the collectivization program. The Stalinist purges of 1936–38 brought additional millions into the camps—said to be essentially institutions of slavery.
Heinrich Himmler's Schutzstaffel (SS) took full control of the police and the concentration camps throughout Germany in 1934–35. Himmler expanded the role of the camps to hold so-called "racially undesirable elements", such as Jews, Gypsies/Romanis/Sintis, Serbs, Poles, disabled people, and criminals. The number of people in the camps, which had fallen to 7,500, grew again to 21,000 by the start of World War II and peaked at 715,000 in January 1945.