Ruthenian language
Spoken language
Ruthenian is an exonymic linguonym for a closely related group of East Slavic linguistic varieties, particularly those spoken from the 15th to 18th centuries in the Grand Duchy of Lithuania and in East Slavic regions of the Polish–Lithuanian... Wikipedia
Language families: Indo-European languages, Slavic languages, and East Slavic languages
Early forms: Proto-Indo-European: Proto-Balto-Slavic > Proto-Slavic > Old East Slavic
Extinct: Developed into Belarusian, Ukrainian and Rusyn
Official language in: Grand Duchy of Lithuania (later replaced by Polish)