The Recovered Territories or Regained Lands (), also known as the Western Borderlands (), and previously as the Western and Northern Territories (), Postulated Territories () and Returning Territories (), was an official term used in the Polish People's Republic to describe 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 term was a political propaganda expression and was systematically employed by Poland's post-war communist government to legitimize the annexation of these territories and the expulsion of the German population.

The rationale for the term "Recovered" was that these territories had formed part of the medieval 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 (small parts of these territories remained under Polish rule even after the end of the Piast dynasty), after the establishment of the state in the Middle Ages. The length of time these territories had been under Polish rule varied considerably. Over the centuries, they had become predominantly German-speaking through the processes of German eastward settlement (), political expansion, 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.

The great majority of the previous inhabitants either fled from the territories during the later stages of the war or were expelled by the Soviet and Polish communist authorities after the war ended, although a small German minority remains in some places. The territories were resettled with Poles who moved from central Poland, Polish repatriates forced to leave areas of former eastern Poland that had been annexed by the Soviet Union, Poles freed from forced labour in Nazi Germany, with Ukrainians forcibly resettled under "Operation Vistula", and other minorities which settled in post-war Poland, including Greeks and Macedonians.

However, contrary to the official declaration that the former German inhabitants of the Recovered Territories had to be removed quickly to house Poles displaced by the Soviet annexation, the Recovered Territories initially faced a severe population shortage. The Soviet-appointed Polish communist authorities that conducted the resettlement also made efforts to remove many traces of German culture, such as place names or historic inscriptions on buildings.

The post-war border between Germany and Poland (the Oder–Neisse line) was recognized by East Germany in 1950 and by West Germany in 1970, and was affirmed by the re-united Germany in the German–Polish Border Treaty of 1990.

Origin and use of the term

The term "Recovered Territories" was officially used for the first time in the Decree of the President of the Republic of 11 October 1938, after the annexation of Trans-Olza by the Polish army.Dziennik Ustaw 1938 no. 78 item 533. It became the official termAn explanation note in "The Neighbors Respond: The Controversy Over the Jedwabne Massacre in Poland" , ed. by Polonsky and Michlic, p. 466 coined in the aftermath of World War II to denote the former eastern territories of Germany that were being handed over to Poland, pending a final peace conference with Germany which eventually never took place.; ; The term "Recovered Territories" is a collective term for different areas with different histories, which can be grouped into three categories: Those that once had been part of the Polish state during the rule of the Piasts, many of which later on had been part of various Piast, Griffin, Jagiellon and Sobieski-ruled duchies, some up to the 17th and 18th century, although often under foreign suzerainty; Those that had been part of Poland until the 17th century (northernmost part of Greater Poland, including Czaplinek) or were under Polish suzerainty as fiefs, in the 15th, 16th and 17th centuries (southern Ducal Prussia and the Duchy of Opole, which also falls into the category above); Territories that had been part of Poland until the Partitions (Warmia, Malbork Voivodeship, parts of Pomerelia, northern Greater Poland including Piła, Wałcz, and Złotów, which were annexed by Prussia in the First Partition of 1772; and Gdańsk and western parts of Greater Poland including Międzyrzecz and Wschowa, which followed in the Second Partition of 1793).

The underlying concept was to define post-war Poland as heir to the medieval Piasts' realm,Joanna B. Michlic, Poland's Threatening Other: The Image of the Jew from 1880 to the Present, 2006, pp. 207–208, , Norman Davies, God's Playground: A History of Poland in Two Volumes, 2005, p. 381ff, , Geoffrey Hosking, George Schopflin, Myths and Nationhood, 1997, p. 153, , which was simplified into a picture of an ethnically homogeneous state that matched post-war borders,Jan Kubik, The Power of Symbols Against the Symbols of Power: The Rise of Solidarity and the Fall of State Socialism in Poland, 1994, pp. 64–65, , as opposed to the later Jagiellon Poland, which was multi-ethnic and located further east.Jan Kubik, The Power of Symbols Against the Symbols of Power: The Rise of Solidarity and the Fall of State Socialism in Poland, 1994, pp. 65, , The argument that this territory in fact constituted "old Polish lands"Alfred M. De Zayas, Nemesis at Potsdam, p. 168 seized on a pre-war concept developed by Polish right-wing circles attached to the SN. As cited by One reason for post-war Poland's favoring a Piast rather than a Jagiellon tradition was Joseph Stalin's refusal to withdraw from the Curzon line and the Allies' readiness to satisfy Poland with German territory instead.Rick Fawn, Ideology and national identity in post-communist foreign policies, 2003, p. 190, , The original argument for awarding formerly German territory to Poland – compensation – was complemented by the argument that this territory in fact constituted former areas of Poland.Joanna B. Michlic, Poland's Threatening Other: The Image of the Jew from 1880 to the Present, 2006, p. 208, , Jan Kubik, The Power of Symbols Against the Symbols of Power: The Rise of Solidarity and the Fall of State Socialism in Poland, 1994, p. 65, , Dmitrow says that "in official justifications for the border shift, the decisive argument that it presented a compensation for the loss of the eastern half of the pre-war Polish territory to the USSR, was viewed as obnoxious and concealed. Instead, a historical argumentation was foregrounded with the dogma, Poland had just returned to "ancient Piast lands". Objections to the Allies' decisions and criticism of the Polish politicians' role at Potsdam were censored. In a commentary for Tribune, George Orwell likened the transfer of the German population to transferring the whole of the Irish and Scottish population. Also, the Piasts were perceived to have defended Poland against the Germans, while the Jagiellons' main rival had been the growing Duchy of Moscow, making them a less suitable basis for post-war Poland's Soviet-dominated situation. The People's Republic of Poland under the Polish Workers' Party thus supported the idea of Poland based on old Piast lands. The question of the Recovered Territories was one of the few issues that did not divide the Polish Communists and their opposition, and there was unanimity regarding the western border. Even the underground anti-Communist press called for the Piast borders, that would end Germanisation and Drang nach Osten.Philipp Ther, Ana Siljak, Redrawing Nations: Ethnic Cleansing in East-Central Europe, 1944–1948, p. 81 The official view was that the Poles had always had the inalienable and inevitable right to inhabit the Recovered Territories, even if prevented from doing so by foreign powers. Furthermore, the Piast concept was used to persuade the Allied Powers, who found it difficult to define a Polish "ethnographic territory", to assume that it would be an intolerable injustice to not "give the territories back".

By 1949, the term "Recovered Territories" had been dropped from Polish communist propaganda, but it is still used occasionally in common language.Gregor Thum, Die fremde Stadt. Breslau nach 1945, 2006, p. 298, , On the grounds that those areas should not be regarded as unique territories within the Polish state, the authorities began to refer to them instead as the "Western and Northern Lands".Martin Åberg, Mikael Sandberg, Social Capital and Democratisation: Roots of Trust in Post-Communist Poland and Ukraine, Ashgate Publishing, 2003, , Google Print, p. 51 Wolff and Cordell say that along with the debunking of communist historiography, "the "recovered territories" thesis [...] has been discarded", and that "it is freely admitted in some circles that on the whole "the recovered territories" had a wholly German character", but that this view has not necessarily been transmitted to the whole of Polish society.Karl Cordell, Stefan Wolff (2005). Germany's Foreign Policy Towards Poland and the Czech Republic: Ostpolitik Revisited , p. 139, , . "In addition ... it has been relatively easy for Polish historians and others to attempt to debunk communist historiography and present a more balanced analysis of the past – and not only with respect to Germany. It has been controversial and often painful, but nevertheless, it has been done. For example, Poland's acquisition in 1945 of eastern German territories is increasingly presented as the price Germany paid for launching a total war, and then having lost it totally. The 'recovered territories' thesis previously applied in almost equal measures by the communists and the Catholic Church has been discarded. Some circles freely admit that, on the whole, "the recovered territories" in fact had a wholly German character. The extent to which this fact transmitted to groups other than the socially and politically engaged is a matter of debate." The term was also used outside Poland. In 1962, Pope John XXIII referred to those territories as the "western lands after centuries recovered", and did not revise his statement, even under pressure of the German embassy. The term is still sometimes considered useful, due to the Polish existence in those lands that was still visible in 1945, by some prominent scholars, such as Krzysztof Kwaśniewski.Krzysztof Kwaśniewski, Smutek anegdot, 2010, p. 93, , also his previous work Adaptacja i integracja kulturowa ludności Śląska po drugiej wojnie światowej 1969

History before 1945

Prior to the migration westward of West Slavic tribes to the area of present-day Poland in late 4th Century, the area was home to numerous Germanic Tribes, such as the Gutones in the Vistula Basin, and the Vandals in Silesia, Greater Poland, Mazovia and Lesser Poland. The subsequent assimilation of the remaining, pre-existing population of Germanic, Celtic, and Baltic tribes that inhabited the area, effectively Polonising much of the area for subsequent centuries.

Several different West Slavic tribes inhabited most of the area of present-day Poland from the 6th century. Duke Mieszko I of the Polans, from his stronghold in the Gniezno area, united various neighboring tribes in the second half of the 10th century, forming the first Polish state and becoming the first historically recorded Piast duke. His realm roughly included all of the area of what would later be named the "Recovered Territories", except for the Warmian-Masurian part of Old Prussia and eastern Lusatia.