What's the best unit to use against the elephants in Age of Empires 2?

Ranged units and siege weapons are effective against war elephants. Certain melee units have a bonus against them as well, such as pikemen and spearmen.

Though pikemen and spearmen do get a bonus when attacking war elephants, the elephants still do great damage to them in return. It takes a significant advantage in numbers to bring them down using this strategy.

Ranged units that can move at a high speed — such as cavalry archers — are the most effective countermeasure, because war elephants move so slowly. Siege weapons can also be used in a pinch, and monks have a high chance of converting the elephants and getting them under the player's control.