Harkavy, Avraham (Albert). HaYehudim U’Sephath HaSlavim [“The Jews and Slavic Languages.”]

The author contends here that prior to the 17th century the lingua franca of the Jews of Russia, Poland and Lithuania was the Slavic languages of their neighbors. He proves this by demonstrating that the Jewish community of the region was descended from ancient Jewish settlements in the Caucasus and Crimea, and not from the Yiddish-speaking immigrants who came from German lands much later. Harkavy’s research on the origin of the Jews of Russia was tied to a political effort to secure equality of rights for Russian Jews.