Latgalian language
Originally Latgalians were a tribe living in modern Vidzeme and Latgale. It is thought that they spoke the Latvian language, which later spread through the rest of modern Latvia, absorbing features of the Old Curonian, Semigallian, Selonian and Livonian languages. The Latgale area became politically separated during the Polish–Swedish wars, remaining part of the Polish–Lithuanian Commonwealth as the Inflanty Voivodeship, while the rest of Latvians lived in lands dominated by Baltic German nobility. Both centuries of separate development and the influence of different prestige languages likely contributed to the development of modern Latgalian as distinct from the language spoken in Vidzeme and other parts of Latvia.
Lithuanians
Lithuanians (, singular "lietuvis/lietuvė") are a Baltic ethnic group, native to Lithuania, where they number around 2,561,300 people. Another million or more make up the Lithuanian diaspora, largely found in countries such as the United States, Argentina, Brazil, Canada, Colombia, Russia, United Kingdom and Ireland. Their native language is Lithuanian, one of only two surviving members of the Baltic language family. According to the census conducted in 2001, 83.45% of the population of Lithuania identified themselves as Lithuanians, 6.74% as Poles, 6.31% as Russians, 1.23% as Belarusians, and 2.27% as members of other ethnic groups. Most Lithuanians belong to the Roman Catholic Church, while the Lietuvininkai who lived in the northern part of East Prussia prior to World War II, were mostly Evangelical Lutherans.