fealty vs obedience

fealty

noun
  • The oath by which this obligation was assumed. 

  • Fidelity to one's lord or master; the feudal obligation by which the tenant or vassal was bound to be faithful to his lord. 

obedience

noun
  • A written instruction from the superior of an order to those under him. 

  • The collective body of persons subject to any particular authority. 

  • Any official position under an abbot's jurisdiction. 

  • The quality of being obedient. 

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