[3] In the aftermath, an impressed Alexander not only reinstated him as his satrap but also granted him dominion over lands to the south-east extending as far as the Hyphasis (Beas).

[13][a] This identification is based on the fact that multiple Greek histories — Indica by Arrian, Geographica by Strabo, and Bibliotheca historica by Diodorus Siculus — note Megasthenes[b] to have described an Indian tribe called Sourasenoi who worshiped one "Herakles" and originated from the lands of Mathura and Yamuna.

[12][15][c] Porus ruled over the tracts between the rivers Hydaspes (Jhelum) and Acesines (Chenab); Strabo noted the territory to contain almost 300 cities.

[16] Years ago, he had visited Alexander in Sogdiana and was treated as an ally; Omphis' rule was confirmed and gifts lavished, but a Macedonian satrap was installed.

[16] In response, Abisares offered submission but Porus refused, leading Alexander to seek a face-off on the bank of Jhelum.

[16] A band of horsemen on chariots led by Porus' son did detect the intrusion and mount a charge but was repelled by Alexander's superior cavalry.

[16] He took a defensive position in the plains, interspersing infantry units with elephants[d] on the front lines and stationing the cavalry and chariots in the wings.

[16] Soon Porus' army was surrounded on all sides, and became easy fodder for Alexander's forces with the cavalry exterminated and most of the elephants captured.

[20] The date of this battle remains disputed; Alexander's forces overran his lands before meeting stiff resistance at a walled Sangala on the other side of the Ravi.

[20] Thereafter, Alexander proceeded unopposed to the Beas and even intended to cross it towards the Gangetic Plain; however, the monsoon was at its peak and his weary troops remained stubborn despite his cajoling and threats.

[20] Porus was thus ratified as the de facto ruler of the entire territory east of the Jhelum, with no European satrap to co-rule with, unlike Ambhi and Abisares.