Final answer:
One of the most common reasons for ancient civilizations to go to war was to gain control of new lands and expand their empires. Wars were fought for territorial raids and capturing captives and riches.
Step-by-step explanation:
One of the most common reasons for ancient civilizations to go to war with one another was to gain control of new lands and expand their empires, proving they were more powerful. Wars were often fought for territorial raids and to capture captives and riches. Diplomatic relationships such as alliances and marriage alliances were also used to prevent war and build bridges between civilizations.