Single combat
Both ancient and medieval warfare did not always rely on the line or phalanx formation . The "Iliad" notably describes the battles of the Trojan war as a series of single encounters on the field , and the medieval code of chivalry , partly inspired by this , encouraged the single combat between individual knights on the battlefield , in which the loser was not usually killed but taken captive for ransom . 
<triplet> chivalry <subj> knight <obj> practiced by