Battle stands as one of poetry's oldest and most central subjects, from Homer's epic clashes to modern free verse depicting industrialized slaughter. Poets have used battle to explore nearly every facet of the human condition, including courage, fear, loss, glory, and futility, with the treatment of battle shifting dramatically over literary history from heroic celebration toward unflinching critique, particularly following the mass casualties of twentieth-century warfare.

A battle is a significant armed engagement between opposing military forces. Battles are the decisive events of warfare, often lasting hours, days, or even months, and involving thousands or millions of combatants. Military history is organized around famous battles—Marathon, Agincourt, Waterloo, Gettysburg, Verdun, Stalingrad—each representing a turning point in civilization's story. A battle differs from a skirmish in scale and consequence; battles can determine the fate of nations. In poetry, the battle serves as the archetypal setting for exploring heroism, horror, camaraderie, and mortality. The chaos of battle, with its noise, smoke, and confusion, provides a powerful backdrop for meditations on human nature. Related terms include engagement, conflict, and pitched battle. The distinction between battle and campaign is important: a campaign comprises multiple battles leading toward a strategic objective.