Present borders: (all country borders marked with blue lines): The present borders of Poland are the result of the negotiations during World War II in Teheran (1943) and Jalta (1945). The allies decided then that the eastern parts of Poland would be passed on the republics of the Soviet Union. The large cities ( Wilno - now Vilnius, Lwow, Grodno, Luck, Stanislawow) were ethnically predominantly or almost exclusively Polish; the countryside in the east consisted of some regions with Polish majority and some areas chiefly Ukrainian, Byelorussian or Lithuanian. After 1945 most of the "eastern" Poles were forced to resettle into the present area of Poland and especially into its new western territories which in turn had been cut off from the "old" Germany: Silesia, Pomerania, southern parts of East Prussia (Mazury Lakes) were cleansed ethnically in a similar way like "old" Poland, and the German majority was driven out to the present Germany. It is assessed that one third of all inhabitants of the pre-war Poland were subject to resettlement during or after the war. Most of the cities were almost completely destroyed (Warsaw, Wroclaw, Gdansk, Szczecin) either by Nazi army or during the liberation by the Red Army.

Poland after the World War I: (marked with a red line): This is Poland as it used to be between 1919(1921)-1939. In contrast to today's area it was slightly bigger and it was positioned more to the east. Poland had not existed as an independent state for 120 years. The conditions for creating the modern Polish state were enabled by the defeat of Germany and Austria in the World War I. The young Polish army also succeeded to detain an offensive of Bolshevik armies and extended its borders on the historical principle farther to the East to areas were contested and after 1945 occupied by the Soviet Union. Poland also annexed Wilno (Vilnius), the capital of Lithuania - on ethnic principle: as its population was predominantly Polish, and on historical principle: the historical Polish-Lithuanian Union. The area was demanded by Lithuania which existed after 1918 as an independent state. Poland contested on the other hand a small area of Upper Silesia which had a Polish majority and was according to the historical principle incorporated into Czechoslovakia. It is also worth noting that the ethnically German Gdansk (Danzig) had a status of a Free City and that there was a corridor between the isolated German territory of East Prussia and German Pomerania. Germans regarded the corridor as a monstrous historical anomaly, although the areas it spanned were ethnically (and before 1772 also historically) Polish. Poland had in the interwar period only a limited access to the sea, the only important harbour being Gdynia. 10% of Poland's population were Jewish, in contrast to the present-day 0,02%.

The borders after 1846 (marked with a purple line): In fact, there was no independent Poland at that time. The line shows merely how the borders among the three dominating powers of Prussia (later Germany), Austria (later Austria-Hungary), and Tsarist Russia shifted in comparison to the momentary situation after the Third Partition of Poland in 1795. The 120-years period of the limited existence or non-existence of Poland covered the age of the Industrial Revolution and the fact which part of Poland was ruled by Germany, Austria or Russian made a lasting imprint on the particular territory. Napoleon's victories were perceived by Poles as a chance for an independence, but it was after his defeat in 1815 after the Vienna congress when Russia allowed on a part of its partition share the P