Heinrich Himmler makes his first visit to the Auschwitz extermination camp and orders it expanded. The result is Auschwitz II, also known as Birkenau. At this time Auschwitz can only accommodate a few thousand prisoners and most of those incarcerated here are Poles.
Himmler wants the new camp to be able to hold at least 30,000, far more than is necessary to deal with partisans and political prisoners. It thus seems clear that Himmler is making preparations for the Holocaust.