harshness vs tyranny

harshness

noun
  • The quality of being harsh. 

tyranny

noun
  • Extreme severity or rigour. 

  • A government in which a single ruler (a tyrant) has absolute power; this system of government. 

  • The office or jurisdiction of an absolute ruler. 

  • Absolute power, or its use. 

  • A system of government in which power is exercised on behalf of the ruler or ruling class, without regard to the wishes of the governed. 

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