affaire d'honneur vs battle royal

affaire d'honneur

noun
  • A duel. 

battle royal

noun
  • A fight involving three or more individuals, teams, or factions; fought until one person, team, or faction is left standing. 

  • A heated discussion or debate. 

How often have the words affaire d'honneur and battle royal occurred in a corpus of books? (source: Google Ngram Viewer )