marquess vs marquis

marquess

noun
  • A title of nobility for a man ranking beneath a duke and above an earl. 

marquis

noun
  • A nobleman in England, France, and Germany, of a rank next below that of duke, but above a count. Originally, the marquis was an officer whose duty was to guard the marches or frontiers of the kingdom. The office has ceased, and the name is now a mere title conferred by letters patent or letters close. 

  • Any of various nymphalid butterflies of the Asian genus Bassarona (or Euthalia). 

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