The Nazi Gau (plural Gaue) system was originally established in a party conference on 22 May 1926, in order to improve administration of the party structure. From 1933 onwards, after the Nazi seizure of power, the "Gaue" increasingly replaced the German states as administrative subdivisions in Germany. On 12 March 1938 Nazi Germany annexed Austria and on 24 May the Austrian provinces were reorganized and replaced by seven Nazi party "Gaue." Under the Ostmarkgesetz law of 14 April 1939 with effect of 1 May, the Austrian "Gaue" were raised to the status of "Reichsgaue" and their Gauleiters were subsequently also named "Reichsstatthalters".