duchy vs royalism

duchy

noun
  • A dominion or region ruled by a duke or duchess. 

royalism

noun
  • Impassioned allegiance to or advocacy of the establishment, maintenance, and/or interests of a particular king, royal house, or kingly dynasty; sometimes extended to the same of a non-royal (i.e., grand ducal, imperial, or other) family or sovereign; often contrasted with monarchism. 

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