Ruthenian — name often used as an equivalent in English for the ethnonym Rusyn. Among its analogues in other non-Slavic European languages are Ruthener in German, ruthene in french, ruten in Italian, and ruten in Hungarian. The English form, Ruthenian, is derived from the Latin Ruthenus (plural: Rutheni) used since the early medieval period to describe the Eastern Christian population living in the Polish-Lithuanian Commonwealth (present-day Belarus and Ukraine) and the Hungarian kingdom (present-day eastern Slovakia and the Transcarpathian oblast of Ukraine). Because of its Latin origin and ties to the Roman Catholic world, Orthodox Rusyns have generally rejected the term Ruthenian and prefer to use the term Carpatho-Russian, or simply Russian as an English-language equivalent of Rusyn.
The lands inhabited by Rusyns have at times been designated Ruthenia in English-language and or western European sources; hence the province of *Subcarpathian Rus’ may be designated as Subcarpathian Ruthenia, or simply Ruthenia.
Paul Robert Magocsi
Entry courtesy of Encyclopedia of Rusyn History and Culture.