Nazism developed several theories concerning races. They claimed to scientifically measure a strict hierarchy among "human races"; at the top was the "Nordic race", then lesser races. At the bottom of this hierarchy were "parasitic" races, or "Untermenschen" ("sub-humans"), which were perceived to be dangerous to society. Lowest of all in the Nazi racial policy were Africans, Gypsies and Jews. The latters were considered to be "Lebensunwertes Leben" ("Life unworthy of life") and were subjected as second-class citizens, expelled from Nazi Germany before being interned in concentration camps, then exterminated during the Holocaust (see Raul Hilberg's description of the various phases of the Holocaust). R. Walther Darré, Reich Minister of Food and Agriculture from 1933 to 1942, popularized the expression "Blut und Boden" ("Blood and Soil"), one of the many terms of the Nazi glossary ideologically used to enforce popular racism in the German population.

Propaganda and implementation of racial theories