Following his triumph over the Achaemenian Empire, Alexander the Great set out to continue his conquest of Asia. His next objective: the Punjab territory. He confronted an Indian prince named Porus in the area between the Hydaspes (Jhelum) and Acesines (Chenab) rivers.
Despite the numerical superiority of Porus's forces, along with the intimidating presence of 200 elephants, Alexander the Great’s troops outflanked Porus's left side. The maneuver provoked a feeling of panic among the elephants. In the end, the extremely mobile cavalry of Alexander proved to be too powerful for the Indian prince’s forces.
In the aftermath of the battle, Alexander the Great, probably impressed by Porus's military flair and spirit, allowed him to retain his kingdom. The prince became an ally and a subordinate ruler to the Macedonian king until he was assassinated, sometime between 321 and 315 BC, by Eudemus, who was one of Alexander the Great's generals prior to Alexander’s death.