horse soldier vs infantry

horse soldier

noun
  • An army member who fights horseback; a cavalry or cavalier. 

infantry

noun
  • A regiment of infantry 

  • Soldiers who fight on foot (on land), as opposed to cavalry and other mounted units, regardless of external transport (e.g. airborne). 

  • The part of an army consisting of infantry soldiers, especially opposed to mounted and technical troops 

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