bey vs potentate

bey

noun
  • in various other places, a prince or nobleman 

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

potentate

noun
  • A powerful leader; a monarch; a ruler. 

  • A self-important person. 

  • A powerful polity or institution. 

  • Someone acting in an important role. 

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