commonwealth vs sovereignhood

commonwealth

noun
  • Republic. Often capitalized, as Commonwealth. 

  • The entirety of a (secular) society, a polity, a state. 

sovereignhood

noun
  • An independent or sovereign territory. 

  • The state or condition of a sovereign; sovereignty. 

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