castellan vs consul

castellan

noun
  • The governor or caretaker entrusted to oversee a castle or keep for its lord. 

consul

noun
  • Either of the two heads of government and state of the Roman Republic or the equivalent nominal post under the Roman and Byzantine Empires. 

  • Any of the three heads of government and state of France between 1799 and 1804. 

  • An official residing in major foreign towns to represent and protect the interests of the merchants and citizens of their country. 

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