primacy vs princedom

primacy

noun
  • The office, rank, or character of a primate, it being the chief ecclesiastical station or dignity in a national church 

  • The state or condition of being prime or first, as in time, place, rank, etc. 

  • the office or dignity of an archbishop 

princedom

noun
  • The rule, rank, estate etc. of a prince. 

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