Slavs
Standardised Slavic languages that have official status in at least one country are: Belarusian, Bosnian, Bulgarian, Croatian, Czech, Macedonian, Montenegrin, Polish, Russian, Serbian, Slovak, Slovene, and Ukrainian.
Slavs
Proto-Slavic, the supposed ancestor language of all Slavic languages, is a descendant of common Proto-Indo-European, via a Balto-Slavic stage in which it developed numerous lexical and morphophonological isoglosses with the Baltic languages. In the framework of the Kurgan hypothesis, "the Indo-Europeans who remained after the migrations [from the steppe] became speakers of Balto-Slavic". Proto-Slavic is defined as the last stage of the language preceding the geographical split of the historical Slavic languages. That language was uniform, and on the basis of borrowings from foreign languages and Slavic borrowings into other languages, cannot be said to have any recognizable dialects – this suggests that there was, at one time, a relatively small Proto-Slavic homeland.