bey vs feudal lord

bey

noun
  • in various other places, a prince or nobleman 

  • A governor of a province or district in the Turkish dominions 

feudal lord

noun
  • A lord in a feudal system, one who bestows fiefs on vassals in exchange for homage, fealty, and obligations of personal services or rent. 

How often have the words bey and feudal lord occurred in a corpus of books? (source: Google Ngram Viewer )