crown jewel vs flagship

crown jewel

noun
  • A valuable part of a company, especially one that is sought by another in a hostile takeover. 

  • A prized possession or asset, originally one making up part of the royal regalia. 

flagship

noun
  • The most important one out of a related group. 

  • The ship occupied by the fleet's commander (usually an admiral); it denotes this by flying his flag. 

  • The ship regarded as most important out of a group, e.g. a nation's navy or company's fleet. 

verb
  • To act as a flagship for. 

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