magnate vs usurper

magnate

noun
  • A person of rank, influence or distinction in any sphere. 

  • In medieval and early modern Italy, a member of a legally defined category of especially wealthy patrician families, often deprived of the right to political participation by republican governments. 

  • Powerful industrialist; captain of industry. 

usurper

noun
  • One who usurps. 

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