Map
Poland's borders 1939–1945
How the borders of the Polish lands changed: from the last days of peace through the fourth partition and German occupation to Poland's post-war move west.
Aug 1939
On the eve of the war
The Second Polish Republic within the borders set in 1920–1922, with Zaolzie since the autumn of 1938. To the west and north it bordered the Third Reich and East Prussia, Danzig was a Free City under the League of Nations, and to the east lay the Soviet Union.
Nov 1939
The fourth partition
After the September Campaign Germany and the USSR divided Poland under the treaty of 28 September 1939. The western and northern lands were annexed to the Reich, the General Government was formed in the centre, the Soviet Union annexed the east and handed Wilno and its region to Lithuania.
Sep 1941
Under German occupation
After Germany attacked the USSR in June 1941, all the lands of the Second Polish Republic were under German occupation. The District of Galicia was added to the General Government, Białystok and its region became a separate district, and the former eastern lands went to the Reichskommissariats Ostland and Ukraine.
1945
Poland moved west
At Yalta and Potsdam the powers based Poland's eastern border on the Curzon Line and moved its western border to the Oder and the Lusatian Neisse. Poland lost its eastern lands to the USSR and gained territory in the west and north, Danzig and the southern part of East Prussia.
- Poland
- Third Reich (with annexed lands)
- German-occupied lands
- USSR
- Lithuania
- Pre-war border of Poland
Borders: OpenHistoricalMap (public domain).