Page "Demographics of Lithuania" Paragraph 9

The Ruthenian language, corresponding to today's Belarusian and Ukrainian, was then called Russian, and was used as one of the chancellery languages by Lithuanian monarchs.

However there are fewer extant documents written in this language than those written in Latin and German from the time of Vytautas.

Later, Ruthenian became the main language of documentation and writing.

In the years that followed, it was the main language of government until the introduction of Polish as the chancellery language of the Lithuanian-Polish Commonwealth in 1697 ; however there are also examples of documents written in Ruthenian from the second half of the 18th century.

The Lithuanian language was used orally in Vilnius, Trakai and Samogitian voivodeships, and by small numbers of people elsewhere.

At the court of Zygmunt August, the last king of the Duchy, both Polish and Lithuanian were spoken.