After long discussion, Germany decided to annex not only all the lands it had surrendered to Poland in 1918 under the Treaty of Versailles, including Danzig, the Polish Corridor, West Prussia and Upper Silesia, but also other territories.
Two decrees by Hitler (Oct. 8 and 12, 1939) provided for the division of the occupied areas of Poland into the following administrative units:
- Reichsgau Wartheland (initially Reichsgau Posen), which included the entire Poznan Voivodship, most of the Lodz Voivodship, five couties of the Pomeranian Voivodship, and one county of the Warsaw Voivodship;
- the remaining area of Pomeranian voivodship, which was incorporated into the Reichsgau Danzig-Westpreussen (initially Reichgau Westpreussen);
- Ciechanow District (Regierungsbezirk Zichenau) consisting of the five northern counties of Warsaw voiivodship (Plock, Plonsk, Sterpe, Ciechanow, Mlawa), which became a part of East Prussia;
- Katowice District (Regierungsbezirk Kattowitz) or unofficially Ost-Oberschlesien (East Upper Silesia); which included Sosnowiec, Będzin, Chryzanow, and Zawiercie counties and parts of Olkusz and Zywiec counties: The area was 94 000 km2 populated by 10 000 000 people.
- Bezirk Bialystok (district of Bialystok), which included the Bialystok, Bielsk Podlaski, Grajewo, Lomza, Sokolka, Volkovysk, and Grodno counties and was "attached" (not incorporated) to East Prussia;
- Bezirke Litauen und Weissrussland – the Polish part of White Russia (today western Belorussia), including the Vilna province, which was incorporated into the Reichskommissariat Ostland;
- Bezirk Wolhynien-Podolien – the Polish province of Volhynia, which was incorporated into the Reichskommissariat Ukraine; and
- East Galicia, which was incorporated into the General-Government and became its fifth district.
