Gau East Prussia (German: Ostpreußen) was an administrative division of Nazi Germany encompassing the province of East Prussia in the Free State of Prussia from 1933 to 1945. Before that, from 1925 to 1933, it was the regional subdivision of the Nazi Party in that area, having been established at a conference in Königsberg on 6 December 1925. In 1939, Gau East Prussia expanded following the annexation of the Klaipėda Region from Lithuania and the occupation of Poland, while a sliver of territory from the gau was transferred to Reichsgau Danzig-West Prussia. After Germany's attack on the USSR, the Belarusian city of Hrodna (German: Garten) also became part of the Gau.