Any war fought by divine command or for a primarily religious purpose. The concept is found in the Bible (e.g., the Book of Joshua) and has played a role in many religions. The Crusades are Europe's best-known example. In Islam, the concept is called jihad. Wars in which religion plays a secondary or exacerbating role are not generally called holy wars.
This entry comes from Encyclopædia Britannica Concise.
For the full entry on holy war, visit Britannica.com.
Seen & Heard
What made you look up holy war? Please tell us what you were reading, watching or discussing that led you here.