A war elephant was an elephant that was trained and guided by humans for combat. The war elephant's main use was to charge the enemy, break their ranks and instill terror and fear. Elephantry is a term for specific military units using elephant-mounted troops.
War elephants played a critical role in several key battles in antiquity, especially in Ancient India. While seeing limited and periodic use in ancient China, they became a permanent fixture in armies of historical kingdoms in Southeast Asia. During classical antiquity they were also used in ancient Persia and in the Mediterranean world within armies of Macedon, Hellenistic Greek states, the Roman Republic and later Empire, and Carthage in North Africa. In some regions they maintained a firm presence on the battlefield throughout the Middle Ages. However, their use declined with the spread of firearms and other gunpowder weaponry in early modern warfare. After this, war elephants became restricted to non-combat engineering and labour roles, as well as being used for minor ceremonial uses. They continued to be used in combat, however, in some parts of the world, such as in Burma, Thailand, and Vietnam, well into the 19th century.