Battle of the Hydaspes (326 BC): Alexander Against King Porus

The Battle of the Hydaspes was fought in May 326 BC between the army of Alexander the Great and the Indian king Porus on the banks of the Hydaspes River, today’s Jhelum, in the Punjab. Alexander crossed the swollen river by night in a storm and defeated an army that included around 200 war elephants. It was his last great pitched battle and one of the most skilful operations of his career.

Background: Alexander enters India

After conquering the Persian Empire, Alexander the Great spent 329–327 BC campaigning in Bactria and Sogdiana, in today’s Afghanistan, Uzbekistan and Tajikistan. In 327 BC he crossed the Hindu Kush into the lands the Persians had once claimed along the Indus.

Early in 326 BC he crossed the Indus and was welcomed at Taxila by its ruler, known to the Greeks as Taxiles (his Indian name is usually given as Ambhi). Taxiles was hostile to his eastern neighbour Porus, whose kingdom lay between the Hydaspes and the Acesines (Chenab) rivers. Porus, probably a Greek form of the dynastic name Paurava, refused to submit and gathered his forces on the far bank of the Hydaspes.

Porus is known only from Greek and Roman sources. Indian texts of the period do not mention him or the battle.

The crossing

The river was wide and running high with snowmelt and the first monsoon rains. Porus placed his army, with its elephants, opposite Alexander’s camp. Horses would not face elephants, so a direct crossing against them was impossible.

Alexander used deception. For many nights his troops made noise and moved up and down the bank as if about to cross, until Porus stopped reacting. He left Craterus with a large force at the main camp in full view, and marched secretly upstream, about 150 stadia (roughly 27 km) according to Arrian, to a wooded headland opposite an island.

During a night of heavy rain and thunder, he ferried across a strike force that Arrian puts at about 5,000 cavalry and 6,000 infantry, using boats and stuffed hide floats. At dawn the troops discovered they had landed on another island, and had to wade a deep channel to reach the true bank.

The battle

Porus sent his son ahead with cavalry and chariots to stop the landing. Arrian gives the force as 2,000 horse and 120 chariots; other figures vary. The chariots bogged down in the mud and Alexander’s cavalry routed them. The prince was killed.

Porus then drew up his main army on firm, sandy ground. Arrian reports about 30,000 infantry, 4,000 cavalry, 300 chariots and 200 elephants, placed at intervals in front of the infantry line. Diodorus gives 50,000 infantry and 130 elephants. These figures are uncertain, but Porus clearly outnumbered the force that had crossed.

Alexander attacked on the Indian left wing with his cavalry, while sending Coenus with two regiments of horse around to strike the Indian cavalry from behind. The Indian horsemen, caught between the two attacks, fled back into the shelter of the elephants.

The Macedonian infantry phalanx, armed with long pikes called sarissas, then advanced against the elephants. Light troops and archers targeted the drivers, or mahouts, and the animals’ trunks and eyes. Wounded and panicking elephants trampled friend and foe alike, and the Indian army was pressed into a mass. Meanwhile Craterus crossed the river with the rest of the army and joined the pursuit.

Arrian says nearly 20,000 Indian infantry and 3,000 cavalry were killed, including two of Porus’ sons, while the Macedonian losses were only about 80 infantry and some 230 cavalry. Diodorus gives over 12,000 Indian and around 1,000 Macedonian dead. Ancient casualty figures for defeated enemies are often exaggerated, and modern historians treat them as rough indications only.

Porus and Alexander

Porus fought on from the back of a large elephant until he was wounded in the shoulder. According to Arrian and Plutarch, when he was brought before Alexander and asked how he wished to be treated, he replied that he should be treated like a king.

Alexander restored him to his kingdom and later added further territory to it. Porus became a valuable ally on the eastern frontier. In the years after Alexander’s death he was murdered by the Macedonian commander Eudemus, probably between 321 and 315 BC.

Near the battlefield, Alexander founded two cities: Nicaea (“Victory”) and Bucephala, named after his famous horse Bucephalus, who died around this time.

Sources and the battlefield

Everything known about the battle comes from Greek and Roman writers who lived centuries later but used eyewitness accounts. Arrian, writing in the 2nd century AD, drew on the lost histories of Ptolemy and Aristobulus, both of whom served on the campaign, and gives the most detailed and generally most trusted narrative. Plutarch quotes a letter supposedly written by Alexander himself about the crossing, while Diodorus and Curtius preserve a different tradition with larger numbers and more dramatic scenes.

The location of the crossing and the battlefield has never been fixed with certainty. The course of the Jhelum has shifted since antiquity, and no remains of the battle have been identified. The archaeologist Aurel Stein argued in the 1930s for a crossing near Jalalpur, where a wooded spur and islands seemed to match Arrian’s description. Other scholars prefer a site further upstream near the modern city of Jhelum. The question remains open.

Alexander celebrated the victory on his coinage. A rare series of large silver coins, often called the “Porus medallions” or elephant medallions, shows a horseman attacking riders on an elephant and, on the other side, Alexander holding a thunderbolt. Most scholars link them to the Indian campaign, and they are among the few objects made in Alexander’s lifetime that refer to a specific event.

Myths and facts

• Myth: Alexander’s army was crushed by Porus and only claimed victory. Fact: All ancient sources describe a Macedonian victory, and Porus’ submission as Alexander’s ally is consistent with that; the battle was hard-fought, but not a defeat.
• Myth: Bucephalus died of wounds received in the battle. Fact: Arrian says the horse died of old age and exhaustion, at about 30 years old, though some later writers say he was wounded.

Key people

• Alexander the Great (356–323 BC): King of Macedon, who planned the crossing and led the cavalry attack.
• Porus: King of the Paurava lands between the Hydaspes and Acesines, defeated but reinstated.
• Craterus: Senior Macedonian general who held the main camp and crossed later.
• Coenus: Cavalry commander whose flanking ride decided the cavalry fight.
• Taxiles (Ambhi): Ruler of Taxila and Alexander’s ally against Porus.

Timeline

• 327 BC, spring: Alexander crosses the Hindu Kush towards India.
• 326 BC, early: Alexander crosses the Indus and is received at Taxila.
• 326 BC, May: Night crossing of the Hydaspes and defeat of Porus.
• 326 BC, summer: The army mutinies at the Hyphasis (Beas) River and refuses to march further east.
• 326 BC, November: Alexander begins the voyage down the Hydaspes towards the Indus and the sea.
• c. 321–315 BC: Porus is killed by Eudemus.

Consequences

The Hydaspes was a victory, but a costly one in terms of morale. Plutarch says the hard fighting blunted the Macedonians’ enthusiasm for going further into India. When Alexander reached the Hyphasis that summer, his troops refused to continue, and he was forced to turn back.

Macedonian control in the Punjab did not last. Within a few years of Alexander’s death, Chandragupta Maurya built a new empire across northern India, and Seleucus I ceded the remaining eastern provinces to him in the Seleucid-Mauryan War.

Why it matters

The Battle of the Hydaspes shows Alexander’s skill at combining deception, river crossing and combined arms against an unfamiliar enemy. It was the furthest east his army fought a major battle and marked the turning point after which the campaign moved home. The story of Porus’ dignity in defeat has been retold in art and literature ever since.