The Ahnenpaß (literally, "ancestor passport") documented the Aryan lineage of citizens of Nazi Germany. It was one of the forms of the Aryan certificate (Ariernachweis) and issued by the "Reich Association of Marriage Registrars in Germany" (Reichsverband der Standesbeamten in Deutschland e. V.).
The term Aryan in this context was used in a sense widely accepted in scientific racism of the time, which assumed a Caucasian race which was sub-divided into Semitic, Hamitic and Aryan (Japhetic) subraces, the latter corresponding to the Indo-European language family; the Nazi ideology limited the category Aryan to certain subgroups, while excluding Slavs as non-Aryan. Nevertheless, the de facto primary objective was to create extensive profiling based on racial data.
The investigation for lineage was not obligatory as it was a major undertaking to research the original documents for birth and marriage. Many Nazi followers had already begun to research their lineage even before law required it (soon after the NSDAP took power on 30 January 1933).
One important law which was issued on 7 April 1933 (after the Nazi assumption of power) was called the Law for the Restoration of the Professional Civil Service, and it required all public servants to be of Aryan descent. The law, however, did not define the term "Aryan" and a subsequent regulation was issued on 11 April as the first legal attempt by the Third Reich to define who was, and who was not, a Jew. Germans aspiring for the document had to prove they didn't descend either from Jews or Slavs. The Ahnenpass could be given out to citizens of other countries, under the condition that they were of "German blood" and it itself stated that Aryans could be located "wherever they might live in the world" The Reich Legislative Gazette, i.e. the official Reichsgesetzblatt, did not use the phrase "of German blood", but instead used the terminology "German or racially related blood".