principality vs sovereigndom

principality

noun
  • A region or sovereign nation headed by a prince or princess. 

  • A spiritual being, specifically in Christian angelology, the fifth level of angels, ranked above powers and below dominions. 

sovereigndom

noun
  • The state, condition, or realm of a sovereign; sovereignty. 

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