crown princess vs sultana

crown princess

noun
  • The heiress apparent to the throne in a royal or imperial monarchy. 

  • The wife of a crown prince. 

sultana

noun
  • A female ruler of a sultanate. 

  • An old form of necklace. 

  • A pale yellow raisin made from a seedless grape. 

  • A type of viol, a cither viol. 

  • A wife or mistress of a sultan. 

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