field marshal vs mareschal

field marshal

noun
  • In certain nations the highest military rank, ranking below only the commander in chief; now essentially disused. 

mareschal

noun
  • A man of the highest military rank in certain countries. 

  • A herald. 

  • An officer of an household. 

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