emir vs king of kings

emir

noun
  • A prince, commander or other leader or ruler in an Islamic nation. 

  • A descendant of the prophet Muhammad. 

king of kings

noun
  • A king who has other kings as subjects; an emperor. 

name
  • Jesus Christ. 

  • The title of an individual king who has other kings as subjects; in particular 

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