In 326 BCE the army of Alexander III of Macedon (“Alexander the Great”) fought the Punjabi king Porus (in Sanskrit sources, the Paurava ruler) on the banks of the river the Greeks called the Hydaspes — today's Jhelum, the westernmost of the Five Rivers. It was the easternmost major battle of Alexander's campaign and the limit of his advance into the subcontinent. That a major battle took place here is Well-established; the details, as we shall see, must be read with more care.
Causes
After conquering the Persian Empire, Alexander crossed the Indus into Punjab in 326 BCE. The ruler of Taxila (Takshashila, near modern Islamabad), Ambhi, submitted and became an ally. Porus, whose kingdom lay in the fertile country between the Jhelum and the Chenab, refused. With Taxila in Alexander's camp and Porus defiant across the river, neither could leave the other unchallenged.
The battle
The two armies faced each other across the monsoon-swollen Jhelum. Alexander disguised his intentions with repeated feints — marches and counter-marches along the bank — then crossed upstream during a night storm to strike Porus's flank. Porus's force included war elephants, which the Macedonians had rarely faced in battle; the Greek accounts describe hard, costly fighting before the Punjabi army was enveloped and defeated.
327–326 BCE
Alexander enters Punjab
The Macedonian army crosses the Indus; Taxila submits, Porus refuses.
Spring 326 BCE
The stand-off on the Jhelum
The armies face each other across the swollen river; Alexander feints for weeks.
326 BCE
The battle
A night crossing upstream in a storm; hard fighting against Porus's elephants; the Punjabi army is surrounded.
Months later
The turn at the Beas
Alexander's exhausted troops refuse to march further east; the campaign turns back.
Aftermath
By tradition, the captured Porus, asked how he wished to be treated, answered “as a king” — and Alexander restored him to rule his territory, and more, as a subordinate ally. The exchange is one of the most repeated lines of ancient history; treat it as the Greek tradition's telling rather than a transcript. Alexander founded two cities near the battlefield, one — Bucephala — named for his horse Bucephalus, who died in the campaign. Soon afterwards, at the Beas (Greek: Hyphasis), his weary army refused to go further east, and the long march back began.
Long-term significance
The battle opened sustained contact between Punjab and the Hellenistic world. Greek political and artistic influence would echo in the region for centuries through the later Indo-Greek kingdoms of the north-west, whose coins, cities, and Gandharan art carry the meeting of the two worlds that began on the Jhelum's banks.
Modern place-names
The Hydaspes is the Jhelum River; the battlefield lay in present-day Punjab, Pakistan, most commonly placed near Bhera or Jhelum city — the exact site is Under discussion. Taxila's ruins, near Islamabad, are a UNESCO World Heritage Site.