The Nazis thought that the Poles where just a waste of their space, they invaded Poland on the first of September. Polish troops fought heroically but ran out of food and water and on September twenty seventh they were forced to surrender. Hitler sent the troops in Poland eastward for "more living space." The central southern areas became the General Government, and in 1941 Germany claimed eastern Poland as well. The Nazi's had a genocidal policy that targeted 3.3 million men children and women for destruction.
During the 1939 invasion of Poland, special action squads of SS and police were arresting or killing the civilians defying the Germans or thought capable to do so. During the summer of 1940 several thousand university professors, teachers, priests, and many others were shot. The mass murders occurred outside Warsaw, in the Kampinos forest near Palmiry and inside the city at the Pawiak prison.
The Germans closed or destroyed schools, museums, libraries and scientific laboratories. They demolished hundreds of monuments to national heroes. German officials then decreed that Polish children's schooling would end after a few years of elementary education. "The sole goal of this schooling is to teach them simple arithmetic - nothing above the number 500, how to write one's name and the doctrine that it is divine law to obey the Germans." Himmler wrote in his May 1940 memorandum.
Beginning in 1939 the SS began to expel Poles and Jews from the Wartherland and the Danzig corridor and move them to the General Government, by the end of 1940 the SS had expelled 325,000 people without warning. Many elderly people and children died. In 1941 the Germans expelled 45,000 more people. In late 1942 the SS also carried out huge expulsions in the General Government uprooting 110,000 poles from 300 villages.
Some Polish children were chosen for Germanization and forbidden to speak Polish and reeducated in SS or other Nazi institutions. Few ever saw their parents again. Many more children were rejected from Germanization; these unfortunate kids were sent to children's homes or killed. 50,000 children were kidnapped from Poland, mostly from orphanages or foster homes.
As the Polish resistance grew stronger, in 1943 after the German defeat at Stalingrad, German reprisal efforts escalated. The Germans destroyed a lot of villages killing women men and kids. Public executions occurred daily.
1.5 million Poles were transported for labor, most against their will, they were forced to wear purple P's on their clothing they had a curfew and were banned from any means of public transportation. 20,000 Poles died at Sachsenhausen, 20,000 at Gross-Rosen 30,000 at Mauthausen and 17,000 at Ravensbruck.