Франциск Скорина
Энциклопедический справочник

The language of Skorina/Skoryna/Skaryna is properly called Ruthenian, that is, pre-Belarusan and pre-Ukrainian—although Skaryna worked exclusively in Belarusan ethnic territory.

If that's not confusing enough, the title page of Skoryna's Bible reads Біблія руска.