Province of Upper Silesia in the context of "Silesian German"

During the later stages of World War II and the post-war period, Reichsdeutsche (German citizens) and Volksdeutsche (ethnic Germans living outside the Nazi state) fled and were expelled from various Eastern and Central European countries, including Czechoslovakia, and from the former German provinces of Lower and Upper Silesia, East Prussia, and the eastern parts of Brandenburg (Neumark) and Pomerania (Farther Pomerania), which were annexed by the Provisional Government of National Unity of Poland and by the Soviet Union.

The idea to expel the Germans from the annexed territories had been proposed by Winston Churchill, in conjunction with the Polish and Czechoslovak governments-in-exile in London since at least 1942. Tomasz Arciszewski, the Polish prime minister in-exile, supported the annexation of German territory but opposed the idea of expulsion, wanting instead to naturalize the Germans as Polish citizens and to assimilate them. Joseph Stalin, in concert with other Communist leaders, planned to expel all ethnic Germans from east of the Oder and from lands which from May 1945 fell inside the Soviet occupation zones. In 1941, his government had already transported Germans from Crimea to Central Asia.

The Province of Lower Silesia (German: Provinz Niederschlesien; Silesian German: Provinz Niederschläsing; Polish: Prowincja Dolny Śląsk; Silesian: Prowincyjŏ Dolny Ślōnsk) was a province of the Free State of Prussia from 1919 to 1945. Between 1938 and 1941 it was reunited with Upper Silesia as the Province of Silesia. The capital of Lower Silesia was Breslau (now Wrocław in Poland). The province was further divided into two administrative regions (Regierungsbezirke), Breslau and Liegnitz.

The province was not congruent with the historical region of Lower Silesia, which now lies mainly in Poland. It additionally comprised the Upper Lusatian districts of Görlitz, Rothenburg and Hoyerswerda in the west, that until 1815 had belonged to the Kingdom of Saxony, as well as the former County of Kladsko in the southeast.

The Recovered Territories or Regained Lands (Polish: Ziemie Odzyskane), also known as the Western Borderlands (Polish: Kresy Zachodnie), and previously as the Western and Northern Territories (Polish: Ziemie Zachodnie i Północne), Postulated Territories (Polish: Ziemie Postulowane) and Returning Territories (Polish: Ziemie Powracające), are the former eastern territories of Germany and the Free City of Danzig that became part of Poland after World War II, at which time most of their German inhabitants were forcibly deported.

The rationale for the term "Recovered" was that these territories formed part of the Polish state, and were lost by Poland in different periods over the centuries. It also referred to the Piast Concept that these territories were part of the traditional Polish homeland under the Piast dynasty (there were their small parts under Poland even after the Piast ended), after the establishment of the state in the Middle Ages. Over the centuries, however, they had become predominantly German-speaking through the processes of German eastward settlement (Ostsiedlung), political expansion (Drang nach Osten), as well as language shift due to Germanisation of the local Polish, Slavic and Baltic Prussian population. Therefore, aside from certain regions such as West Upper Silesia, Warmia and Masuria, as of 1945 most of these territories did not contain sizeable Polish-speaking communities.