Aryanism is an ideology of racial supremacy which views the supposed Aryan race as a distinct and superior racial group which is entitled to rule the rest of humanity. Initially promoted by racist theorists such as Arthur de Gobineau and Houston Stewart Chamberlain, Aryanism reached its peak of influence in Nazi Germany. In the 1930s and 40s, the regime applied the ideology with full force, sparking World War II with the 1939 invasion of Poland in pursuit of Lebensraum, or living space, for the Aryan people. The racial policies which were implemented by the Nazis during the 1930s came to a head during their conquest of Europe and the Soviet Union, culminating in the industrial mass murder of six million Jews and eleven million other victims in what is now known as the Holocaust.
By the late 19th century, a number of later writers, such as the French anthropologist Vacher de Lapouge in his book L'Aryen, argued that this superior branch could be identified biologically by using the cephalic index (a measure of head shape) and other indicators. He argued that the long-headed "dolichocephalic-blond" Europeans, characteristically found in Northern Europe, were natural leaders, destined to rule over more "brachycephalic" (short-headed) peoples. Similar theories were promoted by Arthur de Gobineau and Houston Stewart Chamberlain.
The ideology of Nazism was based upon the conception of the ancient Aryan race being a superior race, holding the highest position in the racial hierarchy and that the Germanic peoples were the most racially pure existing peoples of Aryan stock. The Nazi conception of the Aryan race arose from earlier proponents of a supremacist conception of the race as described by racial theorist figures such as Arthur de Gobineau and Houston Stewart Chamberlain.
Nazi racial theorist Hans F. K. Günther identified the European race as having five subtype races: Nordic, Mediterranean, Dinaric, Alpine, and East Baltic. Günther applied a Nordicist conception that Nordics were the highest in the racial hierarchy amongst these five European subtype races.