lord of the manor vs viscount

lord of the manor

noun
  • The feudal lord of a manor estate. 

viscount

noun
  • A member of the peerage, above a baron but below a count or earl. 

  • Any of various nymphalid butterflies of the genus Tanaecia. Other butterflies in this genus are called earls and counts. 

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