The estimates vary; Professor Elżbieta Trela-Mazur gives the following numbers in regards to the ethnic composition of these areas: 38% Poles (ca.

These territories were largely inhabited by Ukrainians and Belarusians, with minorities of Poles and Jews (see exact numbers in Curzon line).

The annexed parts were controlled by a German administration ruled by a Gauleiter, a system similar in practice to that of the Reich itself.

A German lawyer and prominent Nazi, Hans Frank, was appointed "Governor-General of the occupied Polish territories" on 26 October 1939.

Frank oversaw the segregation of the Jews into Nazi ghettos in the larger cities, particularly Warsaw, and the use of Polish civilians as forced and slave labour in German war industries.

However, in terms of international politics, a far more important victory was won by Joseph Stalin already in 1943, when the Western Allies yielded to his demands during the Tehran Conference, for the annexation of eastern Poland by the Soviet Union.

Following the German surrender, Soviet agencies such as NKVD and SMERSH proceeded to eliminate all structures originating from the prewar Second Polish Republic.