The Polish population transfers in 1944–46 from the eastern half of prewar Poland (also known as the expulsions of Poles from the Kresy macroregion), refer to the forced migrations of Poles towards the end – and in the aftermath – of World War II. Similar policy, enforced by the Soviet Union between 1939 and 1941, targeted ethnic Poles residing in the Soviet zone of occupation in the aftermath of the Nazi-Soviet invasion of Poland. The second wave of expulsions resulted from the retaking of Poland by the Red Army during the Soviet counter-offensive and subsequent territorial shift ratified by the Allies. The postwar population transfers targeting Polish nationals were part of an official Soviet policy which affected over a million Polish citizens removed in stages from the Polish areas annexed by the Soviet Union. After the war, following Soviet demands laid out during the Tehran Conference of 1943, the Kresy macroregion was formally incorporated into the Ukrainian, Belarusian and Lithuanian Republics of the Soviet Union as agreed at the Potsdam Conference of 1945 to which the acting Government of the Republic of Poland in exile was not invited.
The ethnic displacement of Poles was agreed to by the Allied leaders – Franklin D. Roosevelt of the U.S., Winston Churchill of the United Kingdom, and Joseph Stalin of the USSR – during the conferences at both Tehran and Yalta. In effect, it became one of the largest of several post-war expulsions in Central and Eastern Europe which displaced a total of about twenty million people. According to official data, during the state-controlled expulsion between 1945 and 1946, roughly 1,167,000 Poles left the westernmost republics of the Soviet Union, less than 50% of those who registered for population transfer. The next transfer took place after Stalin's death in 1955–59.
The process is variously known as expulsion, deportation, depatriation, or repatriation, depending on the context and the source. The term repatriation, used officially in both communist-controlled Poland and the USSR, was a deliberate manipulation, as deported people were leaving their homeland rather than returning to it. It is also sometimes referred to as the 'first repatriation' action, in contrast with the 'second repatriation' of 1955–59. In a wider context, it is sometimes described as a culmination of a process of "de-Polonization" of the areas during and after the world war. The process was planned and carried out by the communist regimes of the USSR and that of post-war Poland. Many of the repatriated Poles were settled in formerly German eastern provinces, after 1945, the so-called "Recovered Territories" of the People's Republic of Poland.
The history of Polish settlement in what is now Ukraine and Belarus dates back to 1030–31. It intensified after the Union of Lublin in 1569, when most of the territory became part of the newly established Polish-Lithuanian Commonwealth. From 1657 to 1793 some 80 Roman Catholic Churches and monasteries were built in Volhynia alone. The expansion of Catholicism in Lemkivshchyna, Chełm Land, Podlaskie, Brześć land, Galicia, Volhynia and Right bank Ukraine was accompanied by the process of gradual Polonization of the eastern lands. Social and ethnic conflicts arose regarding the differences of religious practices between the Roman Catholic and the Eastern Orthodox adherents already during the Union of Brest in 1595-96 when the Metropolitan of Kiev-Halych broke relations with the Eastern Orthodox Church and placed himself under the authority of the Pope of Rome.
The partitions of Poland towards the end of the 18th century resulted in the expulsions of ethnic Poles from their homes in the east for the first time in the history of the nation. Some 80,000 Poles were escorted to Siberia by the imperial army in 1864 in the single largest deportation action commenced within the Russian Partition. "Books were burned; churches destroyed; priests murdered;" wrote Norman Davies. Meanwhile, Ukrainians were officially considered "part of the Russian people".
The Russian Revolution of 1917 and the Russian Civil War of 1917-1922 brought an end to the Russian Empire. According to Ukrainian sources from the Cold War period, during the Bolshevik revolution of 1917 the Polish population of Kiev was 42,800. In July 1917, when relations between the Ukrainian People's Republic (UNR) and Russia became strained, the Polish Democratic Council of Kiev supported the Ukrainian side in its conflict with Petrograd. Throughout the existence of UNR (1917–21) a separate ministry for Polish affairs headed by M. Mickiewycz was set up by the Ukrainian side in November 1917. In that entire period, some 1,300 Polish schools functioned with 1,800 teachers and 84,000 students in Galicia. In the region of Podolia in 1917 there were 290 Polish schools. Beginning in 1920, the Bolshevik and nationalist terror campaigns of the new war triggered the flight of Poles and Jews from the Soviet Russia to new sovereign Poland. Russia and Ukraine united in 1922 under the Soviet banner. In that year, 120,000 Poles stranded in the east were repatriated west to the Second Polish Republic. Statistical manipulations in their regard appeared in the Soviet census of 1926 where ethnic Poles were marked down as being of Russian or Ukrainian ethnicity.
The new wave of mass deportations of Poles from the western republics of the Soviet Union began in the autumn of 1935 under Stalin. Poles were expelled from the border regions in order to resettle the area with ethnic Russians and Ukrainians. In 1935 alone 1,500 families were deported to Siberia from the Soviet Ukraine. In 1936, a further 5,000 Polish families were deported to Kazakhstan. The deportations were accompanied by the gradual elimination of Polish cultural institutions. Polish language newspapers were closed as were Polish language courses in Pedagogical Institutes in Ukraine. Soon after the wave of deportations, the Soviet NKVD orchestrated the Genocide of Poles in the Soviet Union. The Polish population in the USSR had officially dropped by 165,000 in that period according to official Soviet census of 1937–38; Polish losses in the Ukrainian SSR were about 30 percent.
Amidst several border conflicts, Poland re-emerged as a sovereign state following a century of foreign partitions. The Polish-Ukrainian alliance was unsuccessful and the Polish-Soviet war continued until the Treaty of Riga was signed in 1921. The Soviet Union did not officially exist before 31 December 1922. The disputed territories were split in Riga between the Second Polish Republic and the Soviet Union representing Ukrainian SSR (part of the Soviet Union after 1923). In the following few years in the lands assigned to sovereign Poland some 8,265 Polish farmers settled with the help received from the government. The overall number of settlers in the east was negligible as compared to region's long-term residents. For instance in the Volhynian Voivodeship (1,437,569 inhabitants in 1921) the number of settlers did not exceed 15,000 people (3,128 refugees from Bolshevist Russia, roughly 7,000 members of local administration and 2,600 military settlers). Approximately 4 percent of the newly arrived settlers lived on their land, while the majority either rented their land to local farmers or moved to the cities.
Tensions between the Ukrainian minority in Poland and the Polish government escalated. On 12 July 1930, activists of the Organization of Ukrainian Nationalists (OUN) helped by UVO began the so-called sabotage action, during which Polish estates were burned, roads, rail lines and telephone connections were destroyed. The OUN used terrorism and sabotage in order to force the Polish government into actions that would cause the more moderate Ukrainian politicians ready to negotiate with the Polish state to lose support. OUN directed its violence not only against the Poles, but also against Jews and other Ukrainians who wished for a peaceful resolution to the Polish–Ukrainian conflict.
The 1939 Soviet invasion of Poland resulted in forcible deportation of hundreds of thousands of Polish citizens to distant parts of the Soviet Union. Five years later for the first time the Supreme Soviet formally acknowledged that the Polish nationals expelled in the follow up of the Soviet invasion were not the Soviet citizens, but foreign subjects. Two decrees were signed on 22 June and 16 August 1944 to facilitate the release of Polish nationals from captivity.
After the signing of the secret Molotov-Ribbentrop pact in 1939 between Nazi Germany and the Soviet Union, Germany invaded Western Poland. Two weeks later, the Soviet Union also invaded eastern Poland. As a result, Poland was divided between the Germans and the Soviets (see Polish areas annexed by the Soviet Union). With the annexation of the Kresy in 1939, modern day Western Ukraine was annexed to Soviet Ukraine, and Western Belarus to Soviet Belorussia respectively. Spreading terror throughout the region, the Soviet secret police (NKVD) accompanying the Red Army murdered Polish prisoners of war, and in less than two years, deported up to 1.5 million Polish citizens to Siberia (about 52% ethnic Poles). By 1944, the population of ethnic Poles in Western Ukraine was 1,182,100. The Polish government in exile in London affirmed its position of retaining the 1939 borders. Nikita Khrushchev, however, approached Stalin personally to keep the territories gained through the illegal and secret Molotov-Ribbentrop pact under continued Soviet occupation.
The residents of the Western Ukraine and Byelorussia, as well as those of the Wilno district which had been annexed to the Soviet Union under the Ribentrop-Molotov pact of 23 August and 28 September 1939, had all been under German occupation for between two and half to three years, and were finally annexed to the Soviet Union in 1944. The speedy exodus of Poles from these regions was meant to erase their Polish past and to confirm the fact that the regions were indeed part of the Soviet Union.
The document regarding the resettlement of Poles from Ukrainian and Belorussian SSR to Poland was signed 9 September 1944 in Lublin by Khrushchev and the head of the Polish Committee of National Liberation Edward Osóbka-Morawski (the corresponding document with Lithuanian SSR was signed on 22 September). The document further specified who was eligible for the resettlement, (it was primarily applicable to all Poles and Jews who were citizens of the Second Polish Republic before 17 September 1939 and their families) what property they could take with them and what aid they would receive from the corresponding governments. The resettlement was divided into two phases: first, the eligible citizens were registered as wishing to be resettled; second their request was to be reviewed and approved by the corresponding governments. About 750,000 Poles and Jews from the western regions of Ukraine were deported, as well as about 200,000 from western Belarus and from Lithuanian SSR each. The deportations continued until August 1, 1946.
Toward the end of World War II, tensions between the Polish AK and Ukrainians escalated into the Massacres of Poles in Volhynia led by the nationalist Ukrainian groups including the Organization of Ukrainian Nationalists (OUN) and the Ukrainian Insurgent Army. Although the Soviet government was actively trying to eradicate these organizations, it did little to support the Polish minority; and instead encouraged population transfer. The haste at which repatriation was done was such that the Polish leader Bolesław Bierut was forced to intercede and approach Stalin to retard this repatriation, as the post-war Polish government was overwhelmed by the sudden great number of refugees.
The Soviet "population exchanges" of 1944-1946 ostensibly concerned [in the legal sense, nominal] citizens of prewar Poland, but in fact Poles and Jews were sent west, whereas Ukrainians had to stay in Soviet Ukraine. The real criterion was one of ethnicity, not citizenship. The [exclusively] ethnic criterion was applied to everyone in Volhynia, Ukrainians forced to stay despite their prewar Polish citizenship, Poles and Jews force to leave despite their ancient traditions in the region. Jewish survivors of the Holocaust and Polish survivors of the ethnic cleansing were generally willing to depart. The history of Volhynia, as an ancient multi-confessional society, had come to and end. – Timothy Snyder 
The Polish exile government in London sent out directives to their organizations (see Polish Secret State) in Lwów and other major centers in Eastern Poland to sit fast and not evacuate, promising that during peaceful discussions they would be able to keep Lwów within Poland. Khrushchev as a result of this directive introduced a different approach to dealing with this Polish problem. Until this time, Polish children could receive education in Polish according to the curriculum of pre-war Poland. Overnight this was discontinued and all Polish schools switched to the Soviet Ukrainian curriculum with classes only in Ukrainian and Russian. All males were also told to prepare for mobilization into labor brigades within the Red Army. These actions were introduced specifically to encourage Polish emigration to Poland.
The director of the Middle school in Rokotyniv, Stefania Kubrynowycz stated:
In January 1945, the NKVD arrested 772 Poles in Lviv (where, according to Soviet sources, on October 1, 1944, Poles represented 66.7% of population), among them 14 professors, 6 doctors, 2 engineers, 3 artists, 5 Catholic priests. The reaction to these arrests in the Polish community was extremely negative. The Polish underground press in Lviv characterized these acts as attempts to hasten the deportation of Poles from their city. Those arrested were released after they signed papers agreeing to emigrate to Poland. It is difficult to establish the exact number of Poles expelled from Lviv, between 100,000 and 140,000.
In stark contrast to what took place in the Ukrainian SSR, the communist officials in the Belorussian SSR did not actively support deportation of Poles. Belorussian officials made it difficult for Polish activists to communicate with tuteishians – people who were undecided as to whether they considered themselves Polish or Belarusian. Much of the rural population, which usually had no official documents of identity, were denied the right of repatriation on the basis that they did not have documents stating they were Polish citizens. In what was described as the "fight for the people", Polish officials attempted to get as many people repatriated as possible, while the Belorussian officials tried to retain them, particularly the peasants, while deporting most of the Polish intelligentsia. It is estimated that about 150,000 to 250,000 people were deported from Belarus. Similar numbers were registered as Poles but forced by the Belorussian officials to remain. A similar number were denied registration as Poles in the Belorussian SSR. A symmetric process has taken place in regards to the Belarusian population of the territory of the Białystok Voivodeship, that was partially retained by Poland after World War II.
Part of the different treatment arose from religious identity; unlike in Ukraine, where most Ukrainian Catholics were members of the powerful Ukrainian Uniate church which was often in conflict with the Polish Roman Catholics, most Belarusian Catholics were members of the Latin rite. It was not unheard of for more educated Belarusian Catholics who could speak Polish to identify as "Poles" to be deported out of Stalin's regime to Poland, where religious freedom was somewhat more open; the Belarusian authorities did not want a mass exodus of their population to Poland. Consequently, Latin Rite Catholicism retains a significant presence in Belarus even today, at about 10%.
The Lithuanian repatriation suffered from numerous delays. Local Polish clergy were active agitating against leaving, and the underground press called those who had registered for repatriation traitors, hoping that the post War Peace Conference would assign Vilnius region to Poland. After these hopes vanished, the number of people wanting to leave gradually increased and signed papers for the People's Republic of Poland State Repatriation Office representatives.
Attitudes in the Lithuanian SSR were similar to those of the Belarusian officials. The Lithuanian communist party was dominated by a nationalist faction which supported the removal of the Polish intelligentsia, particularly from the highly disputed Vilnius region. The city of Vilnius itself was considered a historical capital of Lithuania, however in the early 20th century its population was around 60% Polish, 30% Jewish, with only about 2–3% self-declared Lithuanians. The rural Polish population was however seen as important for the economy, and an easy target for assimilation policies (Lithuanization). The repatriation of Poles from Vilnius, on the other hand, was encouraged and facilitated; the result was a rapid depolonization and Lithuanization of the city (80% of the Polish population was removed). Furthermore, Lithuanian ideology declared that many of the individuals who declared themselves as Polish were in fact "polonized Lithuanians". Again, the rural population was denied the right to leave Lithuania due to their lack of official pre-war documentation of Polish citizenship. Contrary to an agreement with Poland, many individuals were threatened with the repayment of debts or with arrests if they chose repatriation. Individuals connected to the Polish resistance (Armia Krajowa and Polish Underground State) were persecuted by the Soviet authorities. In the end, only about 50% of the registered 400,000 people were allowed to leave. Political scientist Dovilė Budrytė estimated that about 150,000 people left for Poland.
Takie postrzeganie „zagranicznych Polaków" potwierdza chociażby tzw. pierwsza kampania powrotowa (zwana niesłusznie repatriacją), którą komuniści zainicjowali niemal od razu po zakończeniu II wojny światowej.
UMEA International Research Group. Abstracts of Presentations.