despotism vs tyranny

despotism

noun
  • government by a singular authority, either a single person or tight-knit group, which rules with absolute power, especially in a cruel and oppressive way. 

tyranny

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

  • The office or jurisdiction of an absolute ruler. 

  • Extreme severity or rigour. 

  • 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 despotism and tyranny occurred in a corpus of books? (source: Google Ngram Viewer )