The Battle of the Hydaspes and the genius of Alexander

This battle is by far the greatest battle Alexander ever fought, yet it also is the one generally overlooked by historians and indeed dwarfed by all previous similar confrontations. The Granicus was Alexander’s first test against the Persians, who had underestimated their adversary. At Issus, Darius appeared in person on the battlefield, but this was not the terrain he had chosen; listening to bad advice, he moved his army to find himself cornered in a far too small area for his massive number of men. Darius fled to save his bare life, meaning he had to challenge Alexander in another fight. This time, at Gaugamela, the terrain was exactly what Darius needed, but Alexander tricked him into opening his defensive lines and eventually charged straight at Darius. Again the king fled and kept running until he was assassinated by one of his kin, Bessus, who promoted himself to be the new king.

At the Hydaspes River, things were entirely different. Alexander’s adversary was Porus, a powerful Indian ruler both in posture and command, who would not budge from his choice location and advantageous position on the east bank of the river Hydaspes.

I think Alexander liked the challenge of this type of battle, one army opposing the other where he could deploy all his strategic skills. This had not happened since Gaugamela, as in Central Asia, he had to adapt his warfare tactics and convert them into a guerrilla war – a far cry from a glorious fight!

So, here we are in May 326 BC. After crossing the Indus River, Alexander moves east. At about 77 km away from the next major river, the Hydaspes (modern Jhelum River), he is informed that Porus has set up his massive line of defense on the opposite river bank, ready to keep the advancing Macedonian army out of his territory.

Porus’ army must have looked very impressive from the onset. Ancient authors describe it as an enormous wall of 30,000 men/infantry interrupted at an equal distance by a towering elephant, of which there were at least 85, depending on the sources. Spread among the foot soldiers were powerful archers using 90cm high bows able to shoot cumbersome large arrows. Some 300 four-horse chariots and 3,000 cavalry completed the setting. Porus, dressed in silver and gold armor, sat on the largest elephant, looming over the entire army – enough to frighten any enemy. Besides, the river at this point was almost 800 meters wide, and at this time of year, an impetuous current without a real fording despite some sandy islets. Ancient sources compare Porus’ army to a vast city wall (infantry) with intermittent towers (elephants).

It was immediately clear to Alexander that there was no way he could cross the river and attack Porus frontally and that he would have to develop a good strategy. At first, he tested his adversary, and for days in a row, he had Ptolemy move his army then upstream, then downstream, shouting and making as much noise as possible, threatening to cross the river. Porus, well-prepared to impede his opponent’s army from crossing, followed course, moving simultaneously up and downstream. As after many days, nothing happened, Porus’ attention relaxed. This was precisely what Alexander had hoped for and while his men were moving back and forth, he explored the river bank further inland and found a wooded island some 28 km upstream, just behind an angle in the Hydaspes River. At that point, the river bank at his side also showed a depression just deep enough to hide his army, both foot and cavalry, from sight. In other words, an almost ideal place to cross the river in spate.

To fool his adversary further, Alexander directed his pavilion to be set up further downstream with his personal squadron standing guard and all his personal royal paraphernalia in sight. He went even as far as to dress his general Attalus in his own attire with the royal chlamys and all so he would easily be confused with Alexander since he had the same build and appearance as his king – at least from a distance. Attalus was also instructed to make excursions to the edge of the river with the king’s entourage to this spot or that to give the impression that he was planning a crossing. What a stratagem!

By now, it all came down to choosing the right moment; clearly, the gods were on Alexander's side. After dark, he decided to make his move when a heavy thunderstorm broke loose at nightfall. Meanwhile, Ptolemy was still marching up and downstream with his troops, and Craterus was left behind to light as many fires and make as much noise as possible to create the impression that the entire army was still there. His instructions were to cross the river and join the battle only when he could see that the Macedonians had broken the Indian lines.

The night was pitch dark, and the Macedonians could hardly see one another, they had to shout to stay in touch, but their voices were dwarfed by the wailing winds and the noise of thunder and lightning. Tempestuous rains drenched the soldiers, who were swamped by the downpour. Fortune definitely was on their side, for under these circumstances, their sounds were not carried over to the enemy lines. It is incredible how Alexander managed to keep his men together during such a spooky night. Despite the blacked-out heavens, he reached the depression near the crossing spot, probably by midnight or soon after. Alexander’s troops must have been exhausted after this horrific night march of nearly thirty kilometers, and the king allowed his men a rest. Just before dawn, when the rain stopped, and the wind died a little, he signaled his forces to embark on the ships and the rafts made of inflated hides with wooden decking. The king launched his own vessel first (of course), and as Porus’ attention was still focused on Ptolemy's feign maneuvers, Alexander and his troops landed unnoticed on the wooded island. From here, Alexander and his men waded through the second part of the river, whose fast-flowing icy waters reached their armpits and submerged the horses to their necks. This action seemed to escape the enemy’s attention until Alexander landed on Porus’ side of the river. The cavalry was first to set foot on land, and Alexander immediately set off in the direction of Porus, instructing the infantry to follow as soon as they had safely crossed the river.

Porus, at first, assumed that his reinforcements were joining him, but his scouts soon discovered that their foe had managed to come across the river. The Indian ruler deployed 100 four-horse chariots and 4,000 cavalry commanded by his son. The force of the chariot is not to be underestimated because each vehicle was manned by six men, two of whom were archers posted on either side of the chariot and two bore shields, and the two remaining men were charioteers armed with javelins. That is at least what Curtius tells us, although we may wonder how he could fit that many men on the small carriage floor.

Fortune once again was at Alexander’s side because, after the recent heavy downpours, the sandy bank was slimy and totally impracticable for these vehicles, which soon became bogged down. Alexander immediately sent his available light infantry to attack them. A wild fight followed as the charioteers desperately tried to get some control over their vehicle, to no avail, and soon they were put out of action. Porus’ son, who had led the operation, was killed in the skirmish.

Unable to impede Alexander’s crossing of the Hydaspes, Porus now had to attack his adversary. He moved north in search of relatively dry sandy land where he could effectively post the majority of his elephants, his greatest weapon, in a massive battle formation. It was immediately clear to Alexander that the Indian formation was fundamentally defensive, allowing him plenty of time to wait for his infantry to catch up with him. After having crossed the second part of the Hydaspes, these men had to take on what usually was a day-march of nearly 30 km. They had already completed an equivalent march the previous night, followed by a rough river crossing. They must have been pretty exhausted by the time they rejoined their king. It was only sensible to allow them a rest before starting the battle. To conceal the presence of his 9,000 infantry and the strategy of his own deployment to Porus, he ordered his 5,300-strong cavalry to keep moving back and forth in front of the Macedonian army. The trick worked, just as Alexander expected.

We don’t know how much rest the army was given before commencing the battle, but Alexander certainly had plenty of time to study the enemy’s position. Porus had again arranged his elephant in the front line, some thirty meters apart, and his foot soldiers filled the gaps by standing in formation behind them. On either side, he has posted his cavalry, protected by the remaining chariots in front of them. Alexander, rightfully so, assumed that Porus would keep his front line together and march in a straight line. He decided to start by eliminating the Indian cavalry to enable the flanking attack he liked so much.

When Alexander’s troops were rested, he moved his infantry to the center facing Porus’ line and all his cavalry to the far right. His instructions were unambiguous. The infantry was to stay put till the Indians were thrown into confusion by the Macedonian cavalry. Coenus and Perdiccas at the head of the Companion cavalry should stay behind at their assigned place till Porus called his cavalry from his own right flank to support his left against Alexander.

The scene is set, and Alexander starts the attack by moving forward in an oblique line away from the trumpeting elephants. Porus’ cavalry followed suit, extending their lines to prevent a flanking attack. However, the Indian ruler soon realized he had to call for horse reinforcements from his right flank. This was precisely what Alexander had anticipated, and conform to the king’s orders, Coenus and Perdiccas moved towards the empty cavalry spot of the enemy. They passed behind the Macedonian infantry, turned behind Porus’ aligned infantry, and fell on the enemy’s cavalry from behind, which by now was totally encircled. At this point, the only solution for Porus was to divide his cavalry in two; one group would face Alexander’s attack and the other the Coenus/Perdiccas forces. Alexander’s timing was perfect, and he could launch his flanking attack, which was a total success. The Indian horsemen fell back into confusion on the elephants who were called in to assist them. At this point, the solid straight line of defense broke down, automatically creating the opportunity for the Macedonian infantry to rush forward and join the action.

[Map from Frank Holt's book 'Alexander the Great and the Mystery of the Elephant Medallions' reproduced with the approval of the author, for which I am genuinely grateful]

One thing is certain, hell broke lose! Porus’ elephants were his greatest strength and probably Alexander’s greatest challenge. The Macedonian king quickly realized that his heavy infantry was ill-equipped to deal with these beasts, and he sent his light-armed troops to poke the elephants and their drivers with arrows and javelins. Curtius graphically describes how enraged elephants trampled the Macedonians and threw others over their heads. Despite a renewed attack by the Indian cavalry, they were no match for the Macedonians. Coenus had joined ranks with Alexander, and together they made successive attacks on the Indian cavalry and infantry. The elephants were forced back onto their own troops through the joint pressure of the Macedonian heavy infantry and the Companion Cavalry. As most of the mahouts had been killed, the cornered beasts trampled to death, both friend and foe. The wounded and bewildered animals could no longer be controlled; maddened by pain and fear, they spread death around them. The Indian cavalry was jammed by the elephants and, having no space to move, suffered severe losses also. The Macedonian infantry had enough room to maneuver and tried to deal at best with the madden elephants, but the trapped Indians suffered severely.

Gradually the elephants became exhausted, and their charges grew weaker. Alexander saw the time right to encircle what remained of the Indian army, signaling his infantry “to lock shields” and advance onto the enemy en masse. Those who could escape through a small gap in the cavalry line did so but were intercepted by Craterus, who by now and according to his instructions had crossed the Hydaspes with fresh troops and joined the fight. The entire battle must have been a grueling carnage!

Although Porus, still towering above the battlefield, had been wounded at least nine times and bled profusely, he kept fighting with undiminished verve until he collapsed. His mahout turned his master’s massive elephant and set in the flight, with Alexander evidently in close pursuit. At this point, Alexander’s horse was shot from under him; some assume this was how and when his dear Bucephalus died, while other sources tell us that his horse died from old age. In any case, Alexander lost some time in his pursuit as he had to mount another horse.

Alexander sent a messenger to Porus asking for his surrender, which he proudly refused. The following events seem to come from some tale about a fearless knight. Flights of missiles of all kinds were hurled toward the Indians and their mighty king, who started to collapse and slid down his mount. His mahout, thinking Porus wanted to dismount, directed the elephant to crouch down on its knees, and automatically, all the other elephants did the same. Thinking that Porus had died, Alexander ordered his body to be stripped. However, as soon as the Macedonians approached, the elephant moved to stand guard over his rider and menaced whoever dared to approach. He then picked up his noble king and put him back on its back. Once again, the Macedonians attacked in full force with an overwhelming amount of missiles until the elephant fell. Porus was laid in a chariot.

Soon word spread that the Indian king was dead, and his army started to flee. For Alexander, the fight was over; he clearly was victorious and sounded his troops' recall. As he went over to Porus and saw him move his eyelids, he could not help but ask why he had not surrendered when offered. According to some sources, Porus seems to have answered that he considered that there was nobody as strong as him “though I knew my own power, I had not yet tested yours.” When asked how he should be treated, Porus responded with the known phrase “as a king.” He evidently won Alexander over not by compassion but by respect. Alexander had Porus’ wounds cared for, and when he recovered against all odds, Alexander restored his kingdom to him and also extended his territory.

[The two action pictures are evidently from Oliver Stone's movie Alexander]