grand dukedom vs rajah

grand dukedom

noun
  • The title of grand duke or grand duchess, with its pertaining privileges and obligations; contrast grand duchy. 

rajah

noun
  • a Hindu prince or ruler in India. 

  • Any of various nymphalid butterflies of the genus Charaxes. 

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