beginning of the end vs knell

beginning of the end

noun
  • The point when something starts to end or become worse. 

knell

noun
  • A sign of the end or demise of something or someone. 

  • The sound of a bell knelling; a toll (particularly one signalling a death). 

verb
  • To ring a bell slowly, especially for a funeral; to toll. 

  • To signal or proclaim something (especially a death) by ringing a bell. 

  • To summon by, or as if by, ringing a bell. 

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