coup vs feather in one's cap

coup

noun
  • A quick, brilliant, and highly successful act. 

  • A coup d'état. 

  • A takeover of one group by another. 

  • A blow against an enemy delivered in a way that shows bravery. 

  • A single roll of the wheel at roulette, or a deal in rouge et noir. 

  • One of various named strategies employed by the declarer to win more tricks, such as the Bath coup. 

verb
  • To make a coup. 

feather in one's cap

noun
  • An accomplishment; particularly one that is flaunted or boasted of. 

  • He thinks it is quite a feather in his cap that he figured it out for himself. 

  • Used other than figuratively or idiomatically: see feather, cap. 

How often have the words coup and feather in one's cap occurred in a corpus of books? (source: Google Ngram Viewer )