Reichsgau

A (plural ) was an administrative subdivision created in a number of areas annexed by Nazi Germany between 1938 and 1945.
Overview.
The term was formed from the words (realm, empire) and , the latter a deliberately medieval-sounding word with a meaning approximately equivalent to "shire". The were an attempt to resolve the administrative chaos resulting from the mutually overlapping jurisdictions and different boundaries of the NSDAP Party , placed under a Party , and the federal states, under a responsible to the Ministry of the Interior (in the Prussian provinces, the equivalent post was that of ). Interior Minister Wilhelm Frick had long desired to streamline the German administration, and the were the result: the borders of party and those of the federal states were to be identical, and the party also occupied the post of . Rival interests and the influence the wielded with Hitler prevented any reform from being undertaken in the "Old Reich" (), which meant Germany in its borders of 1937 before the annexation of other territories like Austria, the , and Bohemia, and the scheme was therefore implemented only in newly-acquired territories. 
There were several :
The East March was subsequently subdivided into seven smaller , generally coterminous with the former Austrian (federal provinces).