margrave vs marquess

margrave

noun
  • A hereditary ruling prince in certain feudal states of the Holy Roman Empire and elsewhere; the titular equivalent became known as marquis or marquess. 

  • A feudal era military-administrative officer of comital rank in the Carolingian empire and some successor states, originally in charge of a border area. 

marquess

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

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