frankpledge vs internecion

frankpledge

noun
  • A form of collective suretyship and punishment under English law among the members of a tithing. 

  • A decener: a member of a tithing bound in frankpledge. 

  • Any group so similarly answerable for the conduct of all its members and liable for collective punishment. 

  • The tithing itself. 

internecion

noun
  • Mutual destruction. 

  • destruction, massacre 

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