flagship vs man-of-war

flagship

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

  • The most important one out of a related group. 

  • 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. 

man-of-war

noun
  • A powerful armed naval vessel, primarily one armed with cannon and propelled by sails; a warship. 

  • A man whose occupation is fighting in wars; a soldier, a warrior. 

  • The Arctic skua (Stercorarius parasiticus). 

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