elderdom vs rulership

elderdom

noun
  • Authority; dominion. 

  • Preeminence; superiority. 

  • The role or influence of an elder or elders. 

  • The authority, rule, or office of an elder. 

  • The state of being an elder, or of being older; elderhood. 

rulership

noun
  • A position in which one rules or has sovereignty over others. 

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