Why were Porus’s war elephants a challenge for Alexander the Great’s army?

At the Battle of the Hydaspes, the war elephants deployed by King Porus presented a significant challenge to Alexander the Great’s army because they were unfamiliar to the Macedonian forces.1

These animals were formidable in battle due to their willingness to charge directly at both men and horses, which often inspired panic in the cavalry’s mounts. Furthermore, their sheer presence on the battlefield disrupted standard military formations.23

Alexander countered this threat through several tactical adjustments:
* Tactical Positioning: Rather than engaging the elephants directly in the center where they were clustered, Alexander concentrated his attacks on the flanks of the Indian army.1
* Weaponry: When forced to engage the elephants, the Macedonian soldiers utilized the sarissa—a pike measuring 13 to 21 feet (4 to 6.5 meters) in length—which proved effective at repelling the animals.1
* Maneuverability: By utilizing his mobile cavalry and mounted archers, Alexander was able to outmaneuver the slower-moving infantry and elephant units, eventually securing victory.4