dictatorship vs sovereignship

dictatorship

noun
  • A type of government where absolute sovereignty is allotted to an individual or a small clique. 

  • Any household, institution, or other organization that is run under such sovereignty or autocracy. 

  • A government which exercises autocratic rule. 

sovereignship

noun
  • The role or status of sovereign. 

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