chiliad vs chiliarchy

chiliad

noun
  • Synonym of chiliarchy: a group of 1000 soldiers commanded by a chiliarch. 

  • Synonym of millennium: a period of 1000 years. 

chiliarchy

noun
  • A regiment of 1000 soldiers, typically commanded by a chiliarch. 

  • A government of 1000 rulers. 

  • The office or position of a chiliarch. 

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