dynast vs princeling

dynast

noun
  • A ruler or governor, especially a hereditary ruler or someone who founded or is part of a dynasty. 

princeling

noun
  • A descendant of some prominent and influential senior communist official in the People's Republic of China. 

  • A minor or unimportant prince. 

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