at war vs martial

at war

prep
  • (typically with with or against) Vigorously opposed (to); in strong conflict (with). 

  • Fighting in a war. 

martial

adj
  • Connected with or relating to armed forces or the profession of arms or military life. 

  • Characteristic of or befitting a warrior; having a military bearing; soldierly. 

  • Of, relating to, or suggestive of war; warlike. 

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