Caesar vs ethnarch

Caesar

noun
  • A title of Roman emperors. 

  • A Bloody Caesar cocktail. 

  • An absolute ruler; an autocrat. 

name
  • An ancient Roman family name, notably that of Julius Caesar. 

  • The government; society; earthly powers. 

ethnarch

noun
  • The governor of a Jewish province under the Roman Empire. 

  • A leader of an ethnic community, especially a Jewish or (in the Ottoman Empire) Eastern Orthodox leader having political as well as spiritual authority. 

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