heroism vs strongheartedness

heroism

noun
  • The qualities characteristic of a hero, such as courage, bravery, fortitude, selflessness, etc.; the display of such qualities. 

strongheartedness

noun
  • Courage, bravery. 

  • Resilience, endurance. 

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