overlordship vs potentate

overlordship

noun
  • The realm of overlords. 

  • The position or quality of being an overlord. 

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 overlordship and potentate occurred in a corpus of books? (source: Google Ngram Viewer )