disloyalty vs fealty

disloyalty

noun
  • The quality of being disloyal. 

  • An act of being disloyal; a betrayal, faithbreach. 

fealty

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

  • The oath by which this obligation was assumed. 

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