loyal vs true-hearted

loyal

adj
  • Faithful to a person or cause. 

  • Having or demonstrating undivided and constant support for someone or something. 

  • Firm in allegiance to a person or institution. 

true-hearted

adj
  • Having a faithful heart; honest; sincere; not faithless or deceitful. 

How often have the words loyal and true-hearted occurred in a corpus of books? (source: Google Ngram Viewer )