beadle vs mayor of the palace

beadle

noun
  • A parish constable, a uniformed minor (lay) official, who ushers and keeps order. 

  • A warrant officer. 

  • An attendant to the minister. 

mayor of the palace

noun
  • In the Merovingian kingdoms, the king’s steward and, by the 7th century, de facto regent. 

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