German-Occupied Poland 

Generalgouvernement

The General Government, also referred to as the General Governorate for the Occupied Polish Region, was a German zone of occupation established after the invasion of Poland by Germany, Slovakia and the Soviet Union in 1939 at the onset of World War II.

The first stamps issued for the occupied Polish territories was a series of Polish stamps overprinted GENERAL-GOUVERNEMENT + eagle, with the value in Polish currency. 

The stamps were issued between the 8th and 18th March 1940. 

Available here is the value shown.

Catalogue Numbers:

Michel DE-GO 31
Stamp Number PL N49
Yvert et Tellier DE-GO 42
Stanley Gibbons PL 384
AFA number DE-GO 26
Unificato DE-PL 42

1940, 8./18. März. Teilauflagen von Marken von Polen mit schwarzem Bdr.-Aufdruck durch die Staatsdruckerei Wien.