diadem vs supremacy

diadem

noun
  • Regal power; sovereignty; empire—considered as symbolized by the crown. 

  • A crown. 

  • An ornamental headband worn as a badge of royalty. 

  • An arch rising from the rim of a crown (rarely also of a coronet), and uniting with others over its centre. 

verb
  • To adorn with a diadem; to crown. 

supremacy

noun
  • Power over all others. 

  • The ideology that a specified group is superior to others or should have supreme power over them. 

  • The quality of being supreme. 

  • A state of privilege for a specified group relative to other people in society. 

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