Poles
Polish people are the sixth largest national group in the European Union. Estimates vary depending on source, though available data suggest a total number of around 60 million people worldwide (with roughly 21 million living outside of Poland, many of whom are not of Polish ethnicity, but Polish nationals). There are almost 38 million Poles in Poland alone. There are also Polish minorities in the surrounding countries including (Germany), and indigenous minorities in the Czech Republic, Hungary, Slovakia, northern and eastern Lithuania, western Ukraine, and western Belarus. There are some smaller indigenous minorities in nearby countries such as Moldova. There is also a Polish minority in Russia which includes indigenous Poles as well as those forcibly deported during and after World War II; the total number of Poles in what was the former Soviet Union is estimated at up to 3 million.
Second Polish Republic
Historically, Poland was a nation of many nationalities. This was especially true after independence was regained in the wake of World War I and the subsequent Polish–Soviet War ending at Peace of Riga. The census of 1921 shows 30.8% of the population consisted of ethnic minorities, compared with a share of 1.6% (solely identifying with a non-Polish ethnic group) or 3.8% (including those identifying with both the Polish ethnicity and with another ethnic group) in 2011. The first spontaneous flight of about 500,000 Poles from the Soviet Union occurred during the reconstitution of sovereign Poland. In the second wave, between November 1919 and June 1924 some 1,200,000 people left the territory of the USSR for Poland. It is estimated that some 460,000 of them spoke Polish as the first language. According to the 1931 Polish Census: 68.9% of the population was Polish, 13.9% were Ukrainian, around 10% Jewish, 3.1% Belarusian, 2.3% German and 2.8% other, including Lithuanian, Czech, Armenian, Russian, and Romani. The situation of minorities was a complex subject and changed during the period.
Poland was also a nation of many religions. In 1921, 16,057,229 Poles (approx. 62.5%) were Roman (Latin) Catholics, 3,031,057 citizens of Poland (approx. 11.8%) were Eastern Rite Catholics (mostly Ukrainian Greek Catholics and Armenian Rite Catholics), 2,815,817 (approx. 10.95%) were Greek Orthodox, 2,771,949 (approx. 10.8%) were Jewish, and 940,232 (approx. 3.7%) were Protestants (mostly Lutheran).