The Nazi theorist Alfred Rosenberg believed that the Nordic race was descended from Proto-Aryans, who he believed had prehistorically dwelt on the North German Plain and may ultimately have originated on the lost continent of Atlantis. The Nazis declared that the Nordics (now referred to as the Germanic peoples), or Aryans as they sometimes called them, were superior to all other races. The Nazis believed they were entitled to expand territorially. This concept is known as Nordicism. The actual policy that was implemented by the Nazis resulted in the Aryan certificate. This document, which was required by law for all citizens of the Reich was the "Lesser Aryan certificate" ("Kleiner Ariernachweis"). This could be obtained through an "Ahnenpass", which required the owner to trace their lineage through baptism, birth certificates or certified proof thereof that all grandparents were of "Aryan descent".