Kyïvan Rus vs Ruthenia

Kyïvan Rus

Ruthenia

name
  • Rus, an East Slavic medieval state (880–12th c), corresponding to what is now Ukraine and Belarus, as well as western Russia. 

  • Western portions of East Slavic lands, including the principalities of Galicia-Volhynia and Kyiv, which united with Lithuania and Poland (14th c–1772), corresponding to what is now Ukraine and Belarus. 

  • Lands inhabited by Ukrainians (Ruthenians) of the former Austrian Empire kingdom of Galicia (1772–1918), corresponding to parts of Western Ukraine. 

  • The territory between Central and Eastern Europe inhabited by Rusyns, on the slopes of the Carpathian Mountains in parts of Ukraine, Poland and Slovakia. 

How often have the words Kyïvan Rus and Ruthenia occurred in a corpus of books? (source: Google Ngram Viewer )