Latgalians were an ancient Baltic tribe.

Latvian, also known as Lettish, is an East Baltic language belonging to the Indo-European language family. It belongs to the Baltic subbranch of the Balto-Slavic branch of the family and it is spoken in the Baltic region. It is the language of Latvians and the official language of Latvia as well as one of the official languages of the European Union. There are about 1.2 million native Latvian speakers in Latvia and 100,000 abroad. Altogether, 2 million, or 80% of the population of Latvia, spoke Latvian in the 2000s, before the total number of inhabitants of Latvia slipped to 1.8 million in 2022. Of those, around 1.16 million or 62% of Latvia's population used it as their primary language at home, though excluding the Latgale and Riga regions it is spoken as a native language in villages and towns by over 90% of the population.