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.
Language policy in Latvia
Before the losses of the Latvian government in the cases "Podkolzina v. Latvia" (ECHR) and "Ignatāne v. Latvia" (UN HRC), a certain level of command in Latvian was asked for eligibility to Parliament and local councils. In practice, this had led to re-examinations of various candidates, at least sometimes unexpected, which prevented Ignatāne and Podkolzina (representatives of the Equal Rights party in the 1997 local and 1998 parliamentary elections) from participation. As of 2011, candidates do not need to prove language proficiency, but elected members of Saeima and local councilors can be deprived of mandate for insufficient command of Latvian.