ancestry vs forefather

ancestry

noun
  • Condition as to ancestors; ancestral lineage; hence, birth or honorable descent. 

  • A series of ancestors or progenitors; lineage, or those who compose the line of natural descent. 

forefather

noun
  • ancestor 

  • cultural ancestor; one who originated an idea or tradition. 

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