Germany Directly Annexes Western Poland and the Former Free City of Danzig

On 8 October, Germany directly annexed western Poland and the former Free City of Danzig and placed the remaining block of territory under administration of the newly established General Government.

The Soviet Union immediately started a campaign of sovietization of the newly acquired areas. This included staged elections, the results of which were used to legitimize the Soviet Union's annexation of eastern Poland. In the aftermath of the invasion, a collective of underground resistance organizations formed the Polish Underground State within the territory of the former Polish state. Many of the military exiles that managed to escape Poland subsequently joined the Polish Armed Forces in the West, an armed force loyal to the Polish government in exile.

In October 1939, Germany directly annexed those former Polish territories along German's eastern border: West Prussia, Poznan, Upper Silesia, and the former Free City of Danzig. The remainder of German-occupied Poland (including the cities of Warsaw, Krakow, Radom, and Lublin) was organized as the so-called Generalgouvernement (General Government) under a civilian governor general, the Nazi party lawyer Hans Frank.