Of course, after the Third Partition of Poland there was no Poland left.

When Poland reappeared after World War I and the Russian Revolution, the Germans lost some land (really, only Posen and West Prussia - see the link below), and from the Austrian Empire, only Galicia was given to Poland. The rest of Poland (the majority) was taken from the Russian Empire (again, see map below - the shaded area is modern Poland, the green borders in the upper right hand map on the screen show where the German, Russian and Austrian Empires met).

When the Soviet Union took the eastern third of this Poland in 1939, they never gave it back. That land became Belarus and Ukraine (in particular, the part of Ukraine where the Ukrainian nationalists had ethnically cleansed 100,000 Poles - their banner is now flying in downtown Kiev), and to compensate the Poles after the war, Stalin moved the western border of Poland to give them more land, thus taking away some of Pomerania and Silesia, as well as all of East Prussia, from Germany. However, of the western two thirds of 1919-1939 Poland, the majority of the land was land that was in the Russian Empire following the Third Partition of Poland. That includes Warsaw, Lublin, Cholm, and Lodz.