Polonization (or Polonisation; ) is the acquisition or imposition of elements of Polish culture, in particular the Polish language. This happened in some historic periods among non-Polish populations of territories controlled or substantially under the influence of Poland. Like other examples of cultural assimilation, Polonization could be either voluntary or forced. It was most visible in cases of territories where the Polish language or culture was dominant or where their adoption could result in increased prestige or social status, as was the case with the nobilities of Ruthenia and Lithuania. To a certain extent, political authorities have administratively promoted Polonization, particularly during the Second Polish Republic and 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. 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 diminishing of the Orthodox Church was the part 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 was not realised by 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 twofold. 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 foreign occupation by the neighboring empires of Russia, Prussia, and Austria-Hungary. However, as a third of recreated