imperatorial vs kingly

imperatorial

adj
  • Commanding; authoritative. 

  • Relating to the title or office of imperator. 

kingly

adj
  • Of or belonging to a king or kings; exercised by a king. 

  • Characteristic of kings, majestic, regal; as befits a king, in the manner of a king. 

adv
  • In a royal manner. 

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