Polonization (or Polonisation; Polish: polonizacja) was the acquisition or imposition of elements of Polish culture, in particular the Polish language, as experienced in some historic periods by the non-Polish populations of territories controlled or substantially influenced by Poland. As with other examples of cultural assimilation, it could either be voluntary or forced and is most visible in the case of territories where the Polish language or culture were dominant or where their adoption could result in increased prestige or social status, as was the case of the nobility of Ruthenia and Lithuania. To a certain extent Polonization was also administratively promoted by the authorities, particularly in the period following World War II.
Polonization can be seen as an example of cultural assimilation. Such a view is widely considered applicable to the times of the Polish-Lithuanian Commonwealth (1569–1795) when the Ruthenian and Lithuanian upper classes were drawn towards the more Westernized Polish culture and the political and financial benefits of such a transition, as well as, sometimes, by the administrative pressure exerted on their own cultural institutions, primarily the Orthodox Church. The conversion to the Roman Catholic (and to a lesser extent, Protestant) faith was often the single most important part of the process. For Ruthenians of that time, being Polish culturally and Roman Catholic by religion was almost the same. This aspect of Polonization that led to the diminishing of the Orthodox Church was the part that was most resented by the Belarusian and Ukrainian masses. In contrast the Lithuanians, who were mostly Catholic, were in danger of losing their cultural identity as a nation, but that did not become evident for the wide masses of Lithuanians until the Lithuanian national renaissance in the middle of the 19th century.
On the other hand, the Polonization policies of the Polish government in the interwar years of the 20th century were again two-folded. Some of them were similar to the mostly forcible assimilationist policies, implemented by other European powers that have aspired to regional dominance (e.g., Germanization, Russification), while others resembled policies carried out by countries aiming at increasing the role of their native language and culture in their own societies (e.g., Magyarization, Rumanization, Ukrainization). For Poles, it was a process of rebuilding Polish national identity and reclaiming Polish heritage, including the fields of education, religion, infrastructure and administration, that suffered under the prolonged periods of foreign occupation by the neighboring empires of Russia, Prussia, and Austria-Hungary. However, as a third of recreated Poland's population was ethnically non-Polish and many felt their own nationhood aspirations thwarted specifically by Poland, large segments of this population resisted to varying extents the policies intended to assimilate them. Part of the country's leadership emphasized the need for the ethnic and cultural homogeneity of the state in the long term. However, the promotion of the Polish language in the administration, public life and, especially education, were perceived by some as an attempt at forcible homogenization. In areas inhabited by ethnic Ukrainians for example, actions of the Polish authorities seen as aiming at restricting the influence of the Orthodox and the Ukrainian Greek Catholic Church caused additional resentment, and were considered to be closely tied to religious Polonization.
History of Polonization
Between the 12th and the 14th centuries many towns in Poland adopted the so-called Magdeburg rights that promoted the towns' development and trade. The rights were usually granted by the king on the occasion of the arrival of migrants. Some, integrated with the larger community, such as merchants who settled there, especially Greeks and Armenians. They adopted most aspects of Polish culture but kept their Orthodox faith. Since the Middle Ages, Polish culture, influenced by the West, in turn radiated East, beginning the long and uneasy process of cultural assimilation.
Polish-Lithuanian Commonwealth (1569–1795)
The Polish influence in the regions began with the 1569 Union of Lublin, when many of the Ruthenian territories formerly controlled by the Grand Duchy of Lithuania were transferred to the Polish Crown.
In the climate of the colonization of sparsely populated  Ruthenian lands by the Polish or Polonized nobility, and peasants from central Poland, persecution and even an attempted ban of the Eastern Orthodox Church in the Polish controlled territories following the Union of Brest which sought to convert the Ruthenian peasantry to Catholicism. The attractions and pressures of Polonization on Ruthenian nobility and cultural elite resulted in almost complete abandonment of Ruthenian culture, traditions and the Orthodox Church by the Ruthenian higher class.
The Lithuanian Grand Duke Jogaila was offered the Polish crown and became Władysław II Jagiełło (reigned 1386–1434). This marked the beginning of the gradual, voluntary Polonization of the Lithuanian nobility. Jagiełło built many churches in pagan Lithuanian land and provided them generously with estates, gave out the lands and positions to the Catholics, settled the cities and villages and granted the biggest cities and towns Magdeburg Rights. The Ruthenian nobility was also freed from many payment obligations and their rights were equalized with those of the Polish nobility.
Under Jogaila successor as a king of Crown Władysław III of Varna, that had no power in the Grand Duchy of Lithuania, (reigned 1434–1444) the Polonization which earlier took place more by force than by other means attained a certain degree of subtlety. Władysław III introduced some more liberal reforms. He expanded the privileges to all Ruthenian nobles, irrespective of their religion, and in 1443 he signed a bull equalizing the Orthodox church in rights with the Roman Catholicism thus alleviating the relationship with the Orthodox clergy. These policies continued under the next king Casimir IV Jagiellon. Still, the mostly cultural expansion of the Polish influence continued since the Ruthenian nobility were attracted by both the glamour of the Western culture and the Polish political order where the magnates became the unrestricted rulers of the lands and serfs in their vast estates.
Some Ruthenian magnates like Sanguszko, Wiśniowiecki and Kisiel, resisted the cultural Polonization for several generations, with the Ostrogski family being one of the most prominent examples. Remaining generally loyal to the Polish state, the magnates, like Ostrogskis, stood by the religion of their forefathers, and supported the Orthodox Church generously by opening schools, printing books in Ruthenian language (the first four printed Cyrillic books in the world were published in Cracow, in 1491) and giving generously to the Orthodox churches' construction. However, their resistance was gradually waning with each subsequent generation as more and more of the Ruthenian elite turned towards Polish language and Catholicism.
Still, with most of the educational system getting Polonized and the most generously funded institutions being to the west of Ruthenia, the Ruthenian indigenous culture further deteriorated. In the Polish Ruthenia the language of the administrative paperwork started to gradually shift towards Polish. By the 16th century the language of administrative paperwork in Ruthenia was a peculiar mix of the older Church Slavonic with the Ruthenian language of the commoners and the Polish language. With the Polish influence in the mix gradually increasing it soon became mostly like the Polish language superimposed on the Ruthenian phonetics. The total confluence of Ruthenia and Poland was seen coming.
As the Eastern Rite Greek-Catholic Church originally created to accommodate the Ruthenian, initially Orthodox, nobility, ended up unnecessary to them as they converted directly into the Latin Rite Catholicism en masse, the Church largely became an hierarchy without followers. The Greek Catholic Church was then used as a tool aimed to split even the peasantry from their Ruthenian roots, still mostly unsuccessfully. The commoners, deprived of their native protectors, sought protection through the Cossacks, who, being fiercely Orthodox, tended also to easily turn to violence against those they perceived as their enemies, particularly the Polish state and what they saw as its representatives, the Poles and generally the Catholics, as well as the Jews.
After several Cossack uprisings, especially the fateful Khmelnytsky uprising, and foreign invasions (like the Deluge), the Commonwealth, increasingly powerless and falling under the control of its neighbours, started to decline, the process which eventually culminated with elimination of the Polish statehood in the end of the 18th century for the next 123 years.
While the Commonwealth's Warsaw Compact is widely considered an example of an unprecedented religious tolerance for its time, the oppressive policies of Poland towards its Eastern Orthodox subjects is often cited as one of the main reasons that brought the state's demise.
Polonization also occurred during times when a Polish state didn't exist, despite the empires that partition Poland applied the policies aimed at reversing the past gains of Polonization or aimed at replacing Polish identity and eradication of Polish national group.
The Polonization took place in the early years of the Prussian partition, where, as a reaction to the persecution of Roman Catholicism during the Kulturkampf, German Catholics living in areas with a Polish majority voluntarily integrated themselves within Polish society, affecting approximately 100,000 Germans in the eastern provinces of Prussia.
According to some scholars[who?] the biggest successes in Polonisation of the non-Polish lands of former Commonwealth were achieved after the Partitions, in times of persecution of Polishness (noted by Leon Wasilewski (1917), Mitrofan Dovnar-Zapolsky (1926)). Paradoxically, the substantial eastward movement of the Polish ethnic territory (over these lands) and growth of the Polish ethnic regions were taking place exactly in the period of the strongest Russian attack on everything Polish in Lithuania and Belarus.
The general outline of causes for that is considered to include the activities of the Roman-Catholic Church and the cultural influence exacted by the big cities (Vilna, Kovno) on these lands, the activities of the Vilna educational district in 19th century–1820s, the activities of the local administration, still controlled by the local Polish or already Polonised nobility up to the 1863–1864 January Uprising, secret (Polish) schools in second half nineteenth to the beginning of the 20th century (tajne komplety) and the influence of the land estates.
Following the demise of the Polish–Lithuanian Commonwealth in the end of the 18th century, the Polonization trends initially continued in Lithuania, Belarus and Polish-dominated parts of Ukraine as the initially liberal policies of the Empire gave the Polish elite significant concessions in the local affairs. Dovnar-Zapolsky notes that the Polonization actually intensified under the liberal rule of Alexander I, particularly due to the efforts of Polish intellectuals who led the Vilnius University which was organized in 1802–1803 from the Academy in Vilna (Schola Princeps Vilnensis), vastly expanded and given the highest Imperial status under the new name Vilna Imperial University (Imperatoria Universitas Vilnensis). By the Emperor's order, the Vilna education district overseen by Adam Czartoryski, a personal friend of Alexander, was greatly expanded to include the vast territories in the West of the Russian Empire stretching to Kiev in south-east and much of the Polish territory and the development of the University, which had no rival in the whole district, received the highest priority of the Imperial authorities which granted it significant freedom and autonomy. With the effort of Polish intellectuals who served the rectors of the University, Hieronim Strojnowski, Jan Śniadecki, Szymon Malewski, as well as Czartoryski who oversaw them, the University became the center of Polish patriotism and culture; and as the only University of the district the center attracted the young nobility of all ethnicities from this extensive region.
With time, the traditional Latin was fully eliminated from the University and by 1816 it was fully replaced by Polish and Russian. This change both affected and reflected a profound change in the Belarusian and Lithuanian secondary schools systems where Latin was also traditionally used as the University was the main source of the teachers for these schools. Additionally, the University was responsible for the textbooks selection and only Polish textbooks were approved for printing and usage.
Dovnar-Zapolsky notes that "the 1800s–1810s had seen the unprecedented prosperity of the Polish culture and language in the former Great Duchy of Lithuania lands" and "this era has seen the effective completion of the Polonization of the smallest nobility, with further reduction of the areal of use of the contemporary Belarusian language. also noting that the Polonization trend had been complemented with the (covert) anti-Russian and anti-Orthodox trends. The results of these trends are best reflected in the ethnic censuses in previously non-Polish territories.
Following the Polish November Uprising aimed at breaking away from Russia, the Imperial policies finally changed abruptly. The University was forcibly closed in 1832 and the following years where characterized by the policies aimed at the assimilationist solution of the "Polish question", the trend that was further strengthen following another unsuccessful January Uprising (1863).
In the 19th century, the mostly unchallenged Polonization trend of the previous centuries had been met staunchly by then "anti-Polish" Russification policy, with temporary successes on both sides, like Polonization rises in mid-1850s and in 1880s and Russification strengthenings in 1830s and in 1860s. Any Polonization of the east and west territories (Russian and German partitions) occurred in the situation were Poles had steadily diminishing influence on the government. Partition of Poland posed a genuine threat to the continuation of Polish language-culture in those regions. As Polonization was centered around Polish culture, policies aimed at weakening and destroying it had a significant impact on weakening Polonization of those regions. This was particularly visible in Russian-occupied Poland, where the Polish culture fared worst, as Russian administration gradually became strongly anti-Polish. After a brief and relatively liberal early period in the early 19th century, where Poland was allowed to retain some autonomy as the Congress Poland puppet state, the situation for Polish culture steadily worsened.
Second Polish Republic (1918–1939)
By the times of Second Polish Republic (1918–1939) much of Poland's previous territory, which were historically mixed Ruthenian and Polish, had Ukrainian and Belorussian majorities. Following the post-World War I rebirth of the Polish statehood, these lands again became disputed but the Poles were more successful than the nascent West Ukrainian People's Republic in the Polish-Ukrainian War of 1918. Approximately one third of the new state's population was non-Catholic, including a large number of Russian Jews who immigrated to Poland following a wave of Ukrainian pogroms which continued until 1921. The Jews were entitled by a peace treaty in Riga to choose the country they preferred and several hundred thousand joined the already large Jewish minority of the Polish Second Republic.
The issue of non-Polish minorities was a subject of intense debate within the Polish leadership. Two ideas of Polish policy clashed at the time; a more tolerant and less assimilationist approach advocated by Józef Piłsudski, and an assimilationist approach advocated by Roman Dmowski and Stanisław Grabski.
Linguistic assimilation was considered by National Democrats to be a major factor for "unifying the state." For example, Grabski as Polish Minister for Religion and Public Education in 1923 and 1925–1926, wrote that "Poland may be preserved only as a state of Polish people. If it were a state of Poles, Jews, Germans, Rusyns, Belarusians, Lithuanians, Russians, it would lose its independence again"; and that "it is impossible to make a nation out of those who have no 'national self-identification,' who call themselves 'local' (tutejszy).". Grabski also said that "the transformation of the state territory of the Republic into a Polish national territory is a necessary condition for maintaining our frontiers."
In internal politics, Piłsudski's reign marked a much-needed stabilization and improvement in the situation of ethnic minorities, which formed almost a third of the population of the Second Republic. Piłsudski replaced the National-Democratic "ethnic-assimilation" with a "state-assimilation" policy: citizens were judged by their loyalty to the state, not by their ethnicity. The years 1926–1935 were favourably viewed by many Polish Jews, whose situation improved especially under the cabinet of Piłsudski’s appointee Kazimierz Bartel. However a combination of various reasons, from the Great Depression, through the Piłsudski's need for support from parties for the parliament's election to the vicious spiral of terrorist attacks by Organization of Ukrainian Nationalists and government pacifications meant that the situation continued to degenerate, despite Piłsudski's efforts.
However, Polonization also created a new educated class among the non-Polish minorities, a class of intellectuals aware of the importance of schooling, press, literature and theatre, who became instrumental in the development of their own ethnic identities.
Polonization in Eastern Borderlands (Kresy)
The 1921 Treaty of Riga made between Polish Second Republic and Soviet Russia with Soviet Ukraine without any participation from Belarusian side left almost half of modern Belarus territories in the hands of Polish Second Republic. The government of Soviet Russia according to the text of the Riga treaty was acting "on behalf of Belarusian Soviet Socialist Republic". Additionally, according to Riga Treaty, Soviet Russia, acting on behalf of Belarus, received from Belarus three Eastern regions, which were returned to Belarus in 1924 and 1926.
The territories of Western Belarus, western Ukraine and the Vilnius region, were incorporated into interwar Poland in 1921 at the Treaty of Riga in which the Polish eastern frontiers had been first defined following the Polish–Soviet War of 1919–1921. At the same time, the government of the new Polish state, with pressure from the Allies agreed to grant political autonomy to Galicia, but not Volhynia.
Territories of Galicia and Volhynia had different backgrounds, different recent histories and different dominant religions. Until the First World War, Galicia with its large Ukrainian Greek Catholic population in the east (around Lwów), and Polish Roman Catholics in the west (around Kraków), was controlled by the Austrian Empire. On the other hand, the Ukrainians of Volhynia, formerly of the Russian Empire (around Równe), were largely Orthodox by religion, and were influenced by strong Russophile trends. Both "Polish officials and Ukrainian activists alike, distinguished between Galician and Volhynian Ukrainians" in their political aims. There was a much stronger national self-perception among the Galician Ukrainians increasingly influenced by OUN. While the Ukrainian Greek Catholic Church (UGCC), which functioned in communion with the Latin Rite Catholicism, could have hoped to receive a better treatment in Poland where the leadership saw Catholicism as one of the main tools to unify the nation – the Poles under Stanisław Grabski saw the restless Galician Ukrainians as less reliable than the Orthodox Volhynian Ukrainians, seen as better candidates for gradual assimilation. That's why the Polish policy in Ukraine initially aimed at keeping Greek Catholic Galicians from further influencing Orthodox Volhynians by drawing the so-called "Sokalski line".
Due to the region's history the Ukrainian Greek Catholic Church attained a strong Ukrainian national character, and the Polish authorities sought to weaken it in various ways. In 1924, following a visit with the Ukrainian Catholic believers in North America and western Europe, the head of the UGCC was initially denied reentry to Lviv for a considerable amount of time. Polish priests led by their bishops began to undertake missionary work among Eastern Rite faithful, and the administrative restrictions were placed on the Ukrainian Greek Catholic Church.
With respect to the Orthodox Ukrainian population in eastern Poland, the Polish government initially issued a decree defending the rights of the Orthodox minorities. In practice, this often failed, as the Catholics, also eager to strengthen their position, had official representation in the Sejm and the courts. Any accusation was strong enough for a particular church to be confiscated and handed over to the Roman Catholic Church. The goal of the two so called "revindication campaigns" was to deprive the Orthodox of those churches that had been Greek Catholic before Orthodoxy was imposed by the tsarist Russian government. 190 Orthodox churches were destroyed, some of the destroyed churches were abandoned, and 150 more were forcibly transformed into Roman Catholic (not Greek Catholic) churches. Such actions were condemned by the head of the Ukrainian Greek Catholic Church, metropolitan Andrei Sheptytsky, who claimed that these acts would "destroy in the souls of our non-united Orthodox brothers the very thought of any possible reunion."
The land reform designed to favour the Poles in mostly Ukrainian populated Volhynia, the agricultural territory where the land question was especially severe, brought the alienation from the Polish state of even the Orthodox Volhynian population who tended to be much less radical than the Greek Catholic Galicians.
During the interwar period of the 20th century (1920–1939), Lithuanian–Polish relations were characterized by mutual enmity. As a consequence of the conflict over the city of Vilnius, and the Polish–Lithuanian War, both governments – in the era of nationalism which was sweeping through Europe – treated their respective minorities harshly. In 1920, after the staged mutiny of Lucjan Żeligowski, Lithuanian cultural activities in Polish controlled territories were limited and the closure of Lithuanian newspapers and the arrest of their editors occurred. One of them – Mykolas Biržiška was accused of state treason and sentenced to the death penalty and only the direct intervention by the League of Nations saved him from being executed. He was one of 32 Lithuanian and Belarusian cultural activists formally expelled from Vilnius on September 20, 1922 and deported to Lithuania. In 1927, as tensions between Lithuania and Poland increased, 48 additional Lithuanian schools were closed and another 11 Lithuanian activists were deported. Following Piłsudski's death in 1935, the Lithuanian minority in Poland again became an object of Polonisation policies with greater intensity. 266 Lithuanian schools were closed after 1936 and almost all Lithuanian organizations were banned. Further Polonisation ensued as the government encouraged settlement of Polish army veterans in the disputed regions. About 400 Lithuanian reading rooms and libraries were closed in Poland between 1936 and 1938. Following the 1938 Polish ultimatum to Lithuania, Lithuania re-established diplomatic relations with Poland and efforts to Polonize Lithuanians living in Poland decreased somewhat.
Post–World War II
During Operation Vistula in 1947, the Ukrainian and Rusyn populations were deported from south-east territories of Poland to northern areas of the territories awarded by the Allies to Poland in the post-war settlement (the Recovered Territories). According to the order of the Ministry of Recovered Territories, "the main goal of the relocation of settlers "W" is their assimilation in a new Polish environment, all efforts should be exerted to achieve those goals. Do not apply the term "Ukrainians" towards the settlers. In cases when the intelligentsia element reaches the recovered territories, they should by all means be settled separately and away from the communities of the "W" settlers."
- In Polish historiography, particularly pre-WWII (e.g., L. Wasilewski. As noted in Смалянчук А. Ф. (Smalyanchuk 2001) Паміж краёвасцю і нацыянальнай ідэяй. Польскі рух на беларускіх і літоўскіх землях. 1864—1917 г. / Пад рэд. С. Куль-Сяльверставай. — Гродна: ГрДУ, 2001. — 322 с. ISBN 978-5-94716-036-9 (2004). Pp.24, 28.), an additional distinction between the Polonization (Polish: polonizacja) and self-Polonization (Polish: polszczenie się) has been being made, however, most modern Polish researchers don't use the term polszczenie się.
- Michael J. Mikoś, Polish Literature from the Middle Ages to the End of the Eighteenth Century. A Bilingual Anthology, Warsaw: Constans, 1999. First chapters online
- Nataliia Polonska-Vasylenko, History of Ukraine, "Lybid", (1993), ISBN 5-325-00425-5, v.I, Section: "Ukraine under Poland"
- Natalia Iakovenko, Narys istorii Ukrainy s zaidavnishyh chasic do kincia XVIII stolittia, Kiev, 1997, Section: 'Ukraine-Rus, the "odd man out" in Rzeczpospolita Obojga Narodow
- "Within the [Lithuanian] grand duchy, the Ruthenian lands initially retained considerable autonomy. The pagan Lithuanians themselves were increasingly converting to Orthodoxy and assimilating into Ruthenian culture. The grand duchy's administrative practices and legal system drew heavily on Slavic customs, and Ruthenian became the official state language. Direct Polish rule in Ukraine since the 1340s and for two centuries thereafter was limited to Galicia. There, changes in such areas as administration, law, and land tenure proceeded more rapidly than in Ukrainian territories under Lithuania. However, Lithuania itself was soon drawn into the orbit of Poland." from Ukraine. (2006). In Encyclopædia Britannica. Retrieved June 3, 2006, from Encyclopædia Britannica Premium Service: 
- Polonska-Vasylenko, Section: Evolution of Ukrainian lands in the 15th–16th centuries
- Piotr S. Wandycz, United States and Poland, Harvard University Press, 1980, p. 16
- "Transferred as a result of the Union of Lublin from the grand duchy of Lithuania to the more ethnically homogeneous Crown, Ukraine was “colonized” by both Polish and Ukrainian great nobles. Most of the latter gradually abandoned Orthodoxy to become Roman Catholic and Polish. These “little kings” of Ukraine controlled hundreds of thousands of “subjects”" from Wladyslaw IV Vasa in "Poland, history of". (2006). In Encyclopædia Britannica. Retrieved June 3, 2006, from Encyclopædia Britannica Premium Service: 
- "Ukraine had flourished under Lithuanian rule, and its language became that of the state; but after the organic union of Poland and Lithuania in 1569, Ukraine came under Polish rule, enserfment of the Ukrainian peasants proceeded apace, and the Ukrainian Orthodox Church suffered persecution." from "Ukraine". The Columbia Encyclopedia, Sixth Edition. 2001–05.
- "The Uniate church was unsuccessful in gaining the legal equality with the Latin church foreseen by the agreement. Nor was it able to stem the process of Polonization and Latinization of the nobility. At the same time, the Union of Brest caused a deep split in the Ruthenian church and society. This was reflected in a sizeable polemical literature, struggles over the control of bishoprics and church properties that intensified after the restoration of an Orthodox hierarchy in 1620, and numerous acts of violence. Efforts to heal the breach in the 1620s and '30s were ultimately fruitless." from Ukraine. (2006). In Encyclopædia Britannica. Retrieved June 3, 2006, from Encyclopædia Britannica Premium Service: 
- In 1596 the Union of Brest-Litovsk subordinated the Eastern Orthodox church of the Commonwealth to the papacy by creating the Eastern-rite (Uniate) church. Politically, this was intended to cement the cohesion of the state vis-à-vis Moscow; instead it led to internal divisions among the Orthodox. The new Eastern-rite church became a hierarchy without followers while the forbidden Eastern Orthodox church was driven underground. Wladyslaw's recognition of the latter's existence in 1632 May have come too late. The Orthodox masses—deprived of their native protectors, who had become Polonized and Catholic—turned to the Cossacks. from Wladyslaw IV Vasa in "Poland, history of". (2006). In Encyclopædia Britannica. Retrieved June 3, 2006, from Encyclopædia Britannica Premium Service: 
- the Lithuanian and Orthodox Rus' nobility in the east were attracted as by a magnet to sixteenth-century Western-oriented Polish culture. Many of them aped Polish customs, adopted the Polish language, and, in the case of the Rus', converted to Roman Catholicism, the official state religion. As for that portion of the Rus' nobility (whether in Lithuania or in Ukraine) who remained Orthodox, Polish political identity became an important element in their outlook. It is precisely from this segment of the Ukrainian nobility that the concept "Gente Ruthenus, natione Polonus" (a Pole of Rus' religion) developed. Paul Robert Magocsi. A History of Ukraine: The Land and Its Peoples. University of Toronto Press. 2010. p. 157.
- Francis Dvornik. The Slavs in European History and Civilization. Rutgers University Press. 1962. p. 307.
- Orest Subtelny, Ukraine: A History, Second Edition, 1994, University of Toronto Press, pp. 89
- The fact that the Polish language was not made the official language of the Commonwealth until 1697, more than three centuries since the dynastic union between the states, testifies to the voluntary nature of the cultural assimilation. From then on, if not before, it was assumed in Poland that Vilnius (or Wilno in Polish) was as Polish as Warsaw. With some exceptions, the Lithuanian upper classes now saw themselves primarily as Poles, albeit of a Lithuanian ethnic background.Thomas Lane. Lithuania stepping westwards. Routledge, 2001. p. 24.
- David James Smith. The Baltic States: Estonia, Latvia and Lithuania. Routledge. 2002. p. 7.
- Romuald J. Misiunas, Rein Taagepera. The Baltic States, years of dependence, 1940–1980. University of California Press. 1983. p. 3.
- "The new Polish king, the son of Jagello, Vladislav [Wladyslaw] named in history "of Varna" due to his death in the battle with Turks at Varna in 1444) curbed significantly the aspirations of Svidrigello [Švitrigaila] by his attitude to the Ruthenian people and the Ruthenian religion. Until that day [under Jagiello] the Poles captured power in Ruthenia by force [...] . Jagiello's successor, Wladyslaw (reigned from 1434), acted differently than his father, although with the same goals in mind. He expanded the privileges and liberties formerly available only to the Ruthenian nobles of the Latin religion to all Ruthenian nobles without exception. This marked the beginning of the reconciliation between Ruthenia and Poland..."
- Kostomarov, "Ostrozhski"
- (Russian) "Little Russian Hetman Zinoviy-Bogdan Khmelnytsky" (Bohdan Khmelnytsky) in "Nikolay Kostomarov's, "Russian History in Biographies of its main figures", 
- William Christian Bullitt, Jr., The Great Globe Itself: A Preface to World Affairs, Transaction Publishers, 2005, ISBN 1-4128-0490-6, Google Print, p.42-43
- John Adams, The Political Writings of John Adams, Regnery Gateway, 2001, ISBN 0-89526-292-4, Google Print, p.242
- The Confederation of Warsaw of 28th of January 1573: Religious tolerance guaranteed, part of the Memory of the World project at UNESCO.
- Aleksandr Bushkov, Andrey Burovsky. Russia that was not – 2. The Russian Atlantis", ISBN 5-7867-0060-7, ISBN 5-224-01318-6
- The Prussian-Polish Situation: An experiment in Assimilation by W.I. Thomas.
- Various authors, The Treaty of Versailles: a reassessment after 75 years, Cambridge University Press, 1998, ISBN 0-521-62132-1, Google Print, p.314
- Roland Sussex, Paul Cubberley, The Slavic Languages, Cambridge University Press, 2007, ISBN 0-521-22315-6, Google Print, p.92
- Mikhail Dolbilov, The Stereotype of the Pole in Imperial Policy: The "Depolonization" of the Northwestern Region in the 1860s, Russian Studies in History, Issue: Volume 44, Number 2 / Fall 2005, Pages: 44 – 88
- Wasilewski L. (Wasilewski 1917) Kresy Wschodnie. – Warszawa: T-wo wydawnicze w Warszawie, 1917. p. VII as cited in (Smalyanchuk 2001), p.24.
- (Dovnar 1926) pp.290–291,298.
- "In times of Myravyov the Hanger", as noted in (Wasilewski 1917), p. VII as cited in (Smalyanchuk 2001), p.24. See also the note on treatment of Polonisation as self-Polonisation.
- As noted in (Wasilewski 1917), p.42 as cited in (Smalyanchuk 2001), p.24. Also noted by Halina Turska in 1930s in "O powstaniu polskich obszarów językowych na Wileńszczyźnie", p.487 as cited in (Smalyanchuk 2001), p.25.
- As noted in (Wasilewski 1917), p.42 as cited in (Smalyanchuk 2001), p.24.
- (Dovnar 1926) pp.290–291,293–298.
- (Smalyanchuk 2001), p.28, (Dovnar 1926), pp.303–315,319–320,328–331,388–389.
- Довнар-Запольский М. В. (Mitrofan Dovnar-Zapolsky) История Белоруссии. – 2-е изд. – Мн.: Беларусь, 2005. – 680 с. ISBN 985-01-0550-X, LCCN 2003-500047
- Tomas Venclova, Four Centuries of Enlightenment. A Historic View of the University of Vilnius, 1579–1979, Lituanus, Volume 27, No.1 – Summer 1981
- Rev. Stasys Yla, The Clash of Nationalities at the University of Vilnius, Lituanus, Volume 27, No.1 – Summer 1981
- Dovnar-Zapolsky, pp.290–298.
- Dovnar-Zapolsky, pp.293–296.
- Dovnar-Zapolsky, pp.303–315,319–320,328–331.
- Harold Nicolson, The Congress of Vienna: A Study in Allied Unity: 1812–1822 , Grove Press, 2001, ISBN 0-8021-3744-X, Google Print, p.171
- THE REBIRTH OF POLAND. University of Kansas, lecture notes by professor Anna M. Cienciala, 2004. Last accessed on 2 June 2006. Quote:"there were large Polish minorities in what is today western Belarus, western Ukraine and central Ukraine. According to the Polish Census of 1931, Poles made up 5,600,000 of the total population of eastern Poland which stood at 13,021,000.* In Lithuania, Poles had majorities in the Vilnius [P. Wilno, Rus. Vilna] and Suwałki areas, as well as significant numbers in and around Kaunas [P.Kowno]."
- "Poland['s] one third of population consisted of non-Poles, many of whom felt bitterly alienated from a state that had forcibly incorporated them into itself... [T]he Polish government felt it had little reason to negotiate terms of autonomy with minorities upon which it had already imposed its rule."
Roshwald, Aviel (2001). http://books.google.com/books?ie=UTF-8&vid=ISBN0415242290&id=qPyer6Pks0oC&pg=PA164&lpg=PA164&dq=%22Peace+of+Riga%22&vq=%22imposed+its+rule%22&sig=O-9FXzZz2mDsX8Gm9U7QwcCYO2s
|chapterurl=missing title (help). Ethnic Nationalism and the Fall of Empires: Central Europe, the Middle East and Russia, 1914–1923. Routledge (UK). ISBN 0-415-24229-0.
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- Zbigniew Brzezinski in his introduction to Wacław Jędrzejewicz’s “Pilsudski A Life For Poland” wrote: Pilsudski’s vision of Poland, paradoxically, was never attained. He contributed immensely to the creation of a modern Polish state, to the preservation of Poland from the Soviet invasion, yet he failed to create the kind of multinational commonwealth, based on principles of social justice and ethnic tolerance, to which he aspired in his youth. One may wonder how relevant was his image of such a Poland in the age of nationalism.... Quoted from this website.
- Rogers Brubaker, Nationalism Reframed: Nationhood and the National Question in the New Europe, Cambridge University Press, 1996, ISBN 0-521-57649-0, Google Print, p.100
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- "Under Tsarist rule the Uniate population had been forcibly converted to Orthodoxy. In 1875, at least 375 Uniate Churches were converted into Orthodox churches. The same was true of many Latin-rite Roman Catholic churches." Orthodox churches were built as symbols of the Russian rule and associated by Poles with Russification during the Partition period 
- The Impact of External Threat on States and Domestic Societie, Manus I. Midlarsky in Dissolving Boundaries, Blackwell Publishers, 2003, ISBN 1-4051-2134-3, Google Print, p.15
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- Роман Дрозд Явожно– трагічний символ акції «Вісла»
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- (Polish) Założenia programowe głównych obozów politycznych wobec szkolnictwa dla ludności białoruskiej w II Rzeczypospolitej
- Subtelny, Orest (1988). Ukraine: A History. Toronto: University of Toronto Press. ISBN 0-8020-5808-6.
- Snyder, Timothy (2004). The reconstruction of nations: Poland, Ukraine, Lithuania, Belarus, 1569–1999. Yale University Press. ISBN 0-300-10586-X.
- Davies, Norman (2005). God's Playground: A History of Poland, Vol. 1: The Origins to 1795. Columbia University Press. ISBN 0-231-12817-7.