Hydaspes 326 BC

[Duncan Head]

We have had a lot on Hydaspes in the last few months, but since I have worked this up for a proposed Hydaspes BattleDay Booklet, it seems a shame not to post the source narrative here as well – though no doubt most of you will have read one translation or another by now.

Battle: Hydaspes, 326 BC

Macedon (King Alexander III, the Great) vs Paurava Indians (King Poros)

Background
Alexander invaded north-west India (modern Pakistan) after his campaigns in Bactria and Sogdia. The king of Taxila submitted to him, but his neighbour Poros refused.

Numbers: Discussed at length in Slingshot 297.

Sources: Several, of which the most important is Arrian, Anabasis of Alexander V.8-19. The version here is taken from the translation of E J Chinnock, published in 1893, modified in places. The chapter-headings are Chinnock's.

Translation:

ARRIAN, BOOK V
CHAPTER VIII. MARCH FROM THE INDUS TO THE HYDASPES.

When Alexander had crossed to the other side of the river Indus, he again offered sacrifice there, according to his custom. Then starting from the Indus, he arrived at Taxila, a large and prosperous city, in fact the largest of those situated between the rivers Indus and Hydaspes. He was received in a friendly manner by Taxiles, the governor of the city, and by the Indians of that place; and he added to their territory as much of the adjacent country as they asked for. Thither also came to him envoys from Abisares, king of the mountain Indians, the embassy including the brother of Abisares as well as the other most notable men. Other envoys also came from Doxareus, the provincial governor, bringing gifts with them. Here again at Taxila Alexander offered the sacrifices which were customary for him to offer, and celebrated a gymnastic and equestrian contest. Having appointed Philip son of Machatas as satrap of the Indians of that district, he left a garrison in Taxila, as well as the soldiers who were invalided by sickness, and then marched towards the river Hydaspes. For he was informed that Porus, with the whole of his army, was on the other side of that river, having determined either to prevent him from making the passage, or to attack him while crossing. When Alexander ascertained this, he sent Coenus son of Polemocrates back to the river Indus, with instructions to cut in pieces all the vessels which he had repaired for the passage of that river, and to bring them to the river Hydaspes. Coenus cut the vessels in pieces and conveyed them thither, the smaller ones being cut into two parts, and the triakonters (thirty-oared galleys) into three. The sections were conveyed upon wagons, as far as the bank of the Hydaspes; and there the vessels were fixed together again, and seen as a fleet upon that river. Alexander took the forces which he had when lie arrived at Taxila, and the 5,000 Indians under the command of Taxiles and the chiefs of that district, and marched towards the same river.

CHAPTER IX. PORUS OBSTRUCTS ALEXANDER'S PASSAGE.
Alexander encamped on the bank of the Hydaspes, and Porus was seen with all his army and his large troop of elephants lining the opposite bank. He remained to guard the passage at the place where he saw Alexander had encamped and sent guards to all the other parts of the river which were more easily fordable, placing officers over each detachment, being resolved to obstruct the passage of the Macedonians. When Alexander saw this, he thought it advisable to move his army in various directions, to distract the attention of Porus, and render him uncertain what to do. Dividing his army into many parts, he himself led some of his troops now into one part of the land and now into another, at one time ravaging the enemy's property, at another looking out for a place where the river might appear easier for him to ford it. The rest of his troops he entrusted to his different generals, and sent them about in many directions. He also conveyed corn from all quarters into his camp from the land on this side the Hydaspes, so that it might be evident to Porus that he had resolved to remain quiet near the bank until the water of the river subsided in the winter, and afforded him a passage in many places. As his vessels were sailing up and down the river, and skins were being filled with hay, and the whole bank appeared to be covered in one place with cavalry and in another with infantry, Porus was not allowed to keep at rest or to bring his preparations together from all sides to any one point if he selected this as suitable for the defence of the passage. Besides at this season all the Indian rivers were flowing with swollen and turbid waters and with rapid currents; for it was the time of year when the sun is wont to turn towards the summer solstice. At this season incessant and heavy rain falls in India; and the snows on the Caucasus, whence most of the rivers have their sources, melt and swell their streams to a great degree. But in the winter they again subside, become small and clear, and are fordable in certain places, with the exception of the Indus, Ganges, and perhaps one or two others. At any rate the Hydaspes becomes fordable.

CHAPTER X. ALEXANDER AND PORUS AT THE HYDASPES.
Alexander therefore spread a report that he would wait for that season of the year, if his passage was obstructed at the present time; but yet all the time he was waiting in ambush to see whether by rapidity of movement he could steal a passage anywhere without being observed. But he perceived that it was impossible for him to cross at the place where Porus himself had encamped near the bank of the Hydaspes, not only on account of the multitude of his elephants, but also because a large army, and that, too, arranged in order of battle and splendidly accoutred, was ready to attack his men as they emerged from the water. Moreover he thought that his horses would refuse even to mount the opposite bank, because the elephants would at once fall upon them and frighten them both by their aspect and trumpeting; nor even before that would they remain upon the inflated hides during the passage of the river; but when they looked across and saw the elephants on the other side they would become frantic and leap into the water. He therefore resolved to steal a crossing by the following manoeuvre. In the night he led most of his cavalry along the bank in various directions, making a clamour and raising the battle-cry in honour of Enyalius. Every kind of noise was raised, as if they were making all the preparations necessary for crossing the river. Porus also marched along the river at the head of his elephants opposite the places where the clamour was heard, and Alexander thus gradually got him into the habit of leading his men along opposite the noise. But when this occurred frequently, and there was merely a clamour and a raising of the battle-cry, Porus no longer continued to move about to meet the expected advance of the cavalry; but perceiving that his fear had been groundless, he kept his position in the camp. However he posted his scouts at many places along the bank. When Alexander had brought it about that the mind of Porus no longer entertained any fear of his nocturnal attempts, he devised the following stratagem.

CHAPTER XI. ALEXANDER'S STRATAGEM TO GET ACROSS.
There was in the bank of the Hydaspes, a projecting point, where the river makes a remarkable bend. It was densely covered by a grove of all sorts of trees; and opposite it in the river was a woody island without a path because it was uninhabited. Perceiving that this island was right in front of the projecting point, and that both the spots were woody and adapted to conceal his attempt to cross the river, he resolved to convey his army over at this place. The projecting point and island were 150 stades distant from his main camp. Along the whole of the bank, he posted sentries, separated as far as was consistent with keeping each other in sight, and easily hearing when any order should be sent along from any quarter. From all sides also during many nights clamours were raised and fires were burnt. But when he had made up his mind to undertake the passage of the river, he openly prepared his measures for crossing opposite the camp.

Craterus had been left behind at the camp with his own cavalry regiment, and the horsemen from the Arachosians and Parapamisadai, as well as the battalions of Alcetas and Polysperchon from the phalanx of the Macedonians, together with the chiefs of the Indians dwelling on this side of the Hyphasis, who had with them 5,000 men. He gave Craterus orders not to cross the river before Porus moved off with his forces against them, or before he ascertained that Porus was in flight and that they were victorious.' "If however," said he, "Porus should take only a part of his army and march against me, and leave the other part with the elephants in his camp, in that case you must still also remain in your present position. But if he leads all his elephants with him against me, and a part of the rest of his army is left behind in the camp, then you must cross the river with all speed. For it is the elephants alone," said he, "which render it impossible for the horses to land on the other bank. The rest of the army can easily cross."

Note: 150 stades is about 27,750 metres, or 17.2 miles.

CHAPTER XII. PASSAGE OF THE HYDASPES.
Such were the orders given to Craterus. Between the island and the great camp where Craterus had been left, he posted Meleager, Attalus, and Gorgias, with the mercenary cavalry and infantry, giving them instructions to cross in detachments, breaking up the army as soon as they saw the Indians already involved in battle.

He then picked the agēma of the Companions, as well as the cavalry regiments of Hephaestion, Perdiccas, and Demetrius, the cavalry from Bactria, Sogdiana, and theScythians, and the Dahai horse-archers; and from the phalanx the hypaspists, the battalions  of Cleitus and Coenus, and the archers and the Agrianes, and made a secret march, keeping far away from the bank of the river, in order not to be seen marching towards the island and the headland, from which he had determined to cross. There the skins were filled in the night with the hay which had been procured long before, and they were tightly stitched up. In the night a furious storm of rain occurred, on account of which his preparations and attempt to cross were still less observed, since the claps of thunder and the storm drowned with their din the clatter of the weapons and the noise which arose from the orders given by the officers. Most of the boats, the triakonters included with the rest, had been cut in pieces by his order and conveyed to this place, where they had been secretly fixed together again and hidden in the wood. At the approach of daylight, both the wind and the rain calmed down; and the rest of the army went over opposite the island, the cavalry mounting upon the skin rafts, and as many of the infantry as the boats would hold getting into those. They went so secretly that they were not observed by the sentinels posted by Porus, before they had already got beyond the island and were only a little way from the other bank.

CHAPTER XIII. PASSAGE OF THE HYDASPES.
Alexander himself embarked in a triakonter and went over, accompanied by the Bodyguards Ptolemy, Perdiccas, and Lysimachus, and Seleucus, one of the Companions, who afterwards became king, and half of the hypaspists; the rest of the hypaspists being conveyed in other triakonters. When the army had got beyond the island, they openly directed their course to the bank; and when the sentinels perceived that they had started, they at once rode off to Porus as fast as each man's horse could gallop. Alexander himself was the first to land, and he at once took the men from the triakonters and drew up the cavalry in proper formation as they kept on landing. For the cavalry had been arranged to land first. At the head of these he advanced in good order. But through ignorance of the locality he had landed on ground which was not a part of the mainland, but an island, one large enough to be mistaken. It was cut off from the rest of the land by a part of the river where the water was shallow. However, the furious storm of rain, which lasted the greater part of the night, had swelled the water so much that his cavalry could not find out the ford; and he was afraid that he would have to undergo another labour in crossing as great as the first. But when at last the ford was found, he led his men through it with much difficulty; for where the water was deepest, it reached higher than the breasts of the infantry; and of the horses only the heads rose above the river. When he had also crossed this piece of water, he selected the agēma of the cavalry, and the best men from the other cavalry regiments, and brought them up from column into line on the right wing. In front of all the cavalry he posted the horse-archers. He  placed next to the cavalry in front of the other infantry the royal hypaspists under the command of Seleucus. Near these he placed the royal agēma, and next to these the other hypaspists, as each happened at the time to have the right of precedence. At the wings of the phalanx on either side he placed the archers and the Agrianes [and] the javelinmen.

CHAPTER XIV. THE BATTLE AT THE HVDASPES.
Having thus arranged his army, he ordered the infantry, which numbered almost 6,000 men, to follow at a slow pace and in regular order; and because he thought he was superior in cavalry, he took only his horse-soldiers, who were 5,000 in number, and led them forward with speed. He also instructed Tauron, the commander of the archers, to lead them on also with speed to back up the cavalry. He had come to the conclusion that if Porus should engage him with all his forces, he would easily be able to overcome him by attacking with his cavalry, or at least resist until his infantry came into the action; but if the Indians should be alarmed at his extraordinary audacity in making the passage of the river and take to flight, he would be able to keep close to them in their flight, so that the more he slaughtered in the retreat, the less work there would be left to do.

Aristobulus says that the son of Porus arrived with about sixty chariots before Alexander made his latter passage from the large island, and that he could have hindered Alexander's crossing (for he made the passage with difficulty even when no one opposed him), if the Indians had leaped clown from their chariots and assaulted those who first emerged from the water. But he passed by with the chariots and thus made the passage quite safe for Alexander; who on reaching the bank sent out his horse-archers against the Indians in the chariots, and these were easily put to rout, many of them being wounded. Other writers say that a battle took place between the Indians, who came with the son of Porus, and Alexander at the head of his cavalry when the passage had been effected, that the son of Porus came with a greater force, that Alexander himself was wounded by him, and that his horse Bucephalas, of which he was exceedingly fond, was killed, being wounded like his master by the son of Porus. But Ptolemy son of Lagos, with whom I agree, gives a different account. This author also says that Porus dispatched his son, but not at the head of merely sixty chariots; nor is it indeed likely that Porus hearing from his scouts that either Alexander himself or at any rate a part of his army had effected the passage of the Hydaspes, would send his son against him with only sixty chariots. These indeed were too many to be sent out as a scouting party, and not adapted for speedy retreat; but they were by no means a sufficient force to keep back those of the enemy who had not yet got across, as well as to attack those who had already landed. Ptolemy says that the son of Porus arrived at the head of 2,000 cavalry and 120 chariots; but that Alexander had already made even the last passage from the island before he appeared.

CHAPTER XV. ARRANGEMENTS OF PORUS.
Ptolemy also says that Alexander in the first place sent the horse-archers against these, and led the cavalry himself, thinking that Porus was approaching with all his forces, and that this body of cavalry was marching in front of the rest of his army, being drawn up by him as the vanguard. But as soon as he had ascertained with accuracy the number of the Indians, he immediately made a rapid charge upon them with the cavalry around him. When they perceived that Alexander himself and the body of cavalry around him had made the assault, not in line of battle regularly formed, but by squadrons, they gave way; and 400 of their cavalry, including the son of Porus, fell in the contest. The chariots also were captured, horses and all, being heavy and slow in the retreat, and useless in the action itself on account of the muddy ground.

When the horsemen who had escaped from this rout brought news to Porus that Alexander himself had crossed the river with the strongest part of his army, and that his son had been slain in the battle, he nevertheless could not make up his mind what course to take, because the men who had been left behind under Craterus were seen to be attempting to cross the river from the great camp which was directly opposite his position. However, at last he preferred to march against Alexander himself with all his army, and to come into a decisive conflict with the strongest division of the Macedonians, commanded by the king in person. But nevertheless he left a few of the elephants together with a small force there at the camp to frighten the cavalry under Craterus from the bank of the river. He then took all his cavalry to the number of 4,000 men, all his chariots to the number of 300, with 200 of his elephants and all the infantry available to the number of 30,000, and marched against Alexander. When he found a place where he saw there was no mud, but that on account of the sand the ground was all level and hard, and thus fit for the advance and retreat of horses, he there drew up his army.
First he placed the elephants in the front, each animal being not less than a plethron apart, so that they might be extended in the front before the whole of the phalanx of infantry, and produce terror everywhere among Alexander's cavalry. Besides he thought that none of the enemy would have the audacity to push themselves into the spaces between the elephants, the cavalry being deterred by the fright of their horses; and still less would the infantry do so, it being likely they would be kept off in front by the heavy-armed soldiers falling upon them, and trampled down by the elephants wheeling round against them. Near these he had posted the infantry, not occupying a line on a level with the beasts, but in a second line behind them, only so far behind that the companies of foot might be thrown forward a short distance into the spaces between them. He had also bodies of infantry standing beyond the elephants on the wings; and on both sides of the infantry he had posted the cavalry, in front of which were placed the chariots on both wings of his army.

Note: A plethron is 100 Greek feet, that is about 31.5 metres or 103 modern feet.

CHAPTER XVI. ALEXANDER'S TACTICS.
Such was the arrangement which Porus made of his forces. As soon as Alexander observed that the Indians were drawn up in order of battle, he stopped his cavalry from advancing further, so that he might take up the infantry as they kept on coming up. Even when the phalanx in quick march had effected a junction with the cavalry, he did not at once draw it out and lead it to the attack, not wishing to hand over his men exhausted with fatigue and out of breath, to the barbarians who were fresh and were not tired. On the contrary, he caused his infantry to rest until their strength was recruited, riding along round the lines to inspect them. When he had surveyed the arrangement of the Indians, he resolved not to advance against the centre, in front of which the elephants had been posted with a compact phalanx of men arranged in the gaps between them; for he was alarmed at the very arrangements which Porus had made here with that express design. But as he was superior in the number of his cavalry, he took the greater part of that force, and marched along against the left wing of the enemy for the purpose of making an attack in this direction. Against the right wing he sent Coenus with his own regiment of cavalry and that of Demetrius, with instructions to keep close behind the barbarians when they, seeing the dense mass of cavalry opposed to them, should ride out to fight them. Seleucus, Antigenes, and Tauron were ordered to lead the phalanx of infantry, but not to engage in the action until they observed the enemy's cavalry and phalanx of infantry thrown into disorder by the cavalry under his own command. But when they came within range of missiles, he launched the horse-archers, 1,000 in number, against the left wing of the Indians, in order to throw those of the enemy who were posted there into confusion by the incessant storm of arrows and by the charge of the horses. He himself with the Companion cavalry marched along rapidly against the left wing of the barbarians, being eager to attack them in flank while still in a state of disorder, before their cavalry could be deployed in line.

CHAPTER XVII. DEFEAT OF PORUS.
Meanwhile the Indians had collected their cavalry from all parts, and were riding along, advancing out of their position to meet Alexander's charge. Coenus also appeared with his men in their rear, according to his instructions. The Indians, observing this, were compelled to make the line of their cavalry face both ways; the largest and best part against Alexander, while the rest wheeled round against Coenus and his forces. This therefore at once threw the ranks as well as the decisions of the Indians into confusion. Alexander, seeing his opportunity, at the very moment the cavalry was wheeling round in the other direction, made an attack on those opposed to him with such vigour that the Indians could not sustain the charge of his cavalry, but were scattered and driven to the elephants, as to a friendly wall, for refuge. Upon this, the drivers of the elephants urged forward the beasts against the cavalry but now the phalanx itself of the Macedonians advanced against the elephants, shooting the drivers with javelins, and shooting from every side on the beasts themselves. The action was unlike any of the previous contests; for wherever the beasts could wheel round, they rushed forth against the ranks of infantry and demolished the phalanx of the Macedonians, dense as it was. The Indian cavalry also, seeing that the infantry were engaged in the action, rallied again and advanced against the Macedonian cavalry. But when Alexander's men, who far excelled both in strength and military discipline, got the mastery over them the second time, they were again repulsed towards the elephants and cooped up among them. By this time the whole of Alexander's cavalry had collected into one squadron, not by any command of his, but having settled into this arrangement by the mere effect of the struggle itself; and wherever it fell upon the ranks of the Indians they were broken lip with great slaughter. The beasts being now cooped up into a narrow space, their friends were no less injured by them than their foes, being trampled down in their wheeling and pushing about. Accordingly there ensued a great slaughter of the cavalry, cooped up as it was in a narrow space around the elephants. Most of the keepers of the elephants had been killed by the javelins, and some of the elephants themselves had been wounded, while others no longer kept apart in the battle on account of their sufferings or from being destitute of keepers. But, as if frantic with pain, rushing forward at friends and foes alike, they pushed about, trampled down and killed them in every kind of way. However, the Macedonians inasmuch as they were attacking the beasts in an open space and in accordance with their own plan, retreated whenever they charged at them; but keeping close behind them when they turned and throwing javelins at them; whereas the Indians retreating among them were now receiving greater injury from them. But when the beasts were tired out, and were no longer able to charge with any vigour, they began to retire slowly, facing the foe like ships backing water, merely uttering a shrill piping sound. Alexander himself surrounded the whole line with his cavalry, and gave the signal that the infantry should link their shields together so as to form a very densely closed body, and thus advance in phalanx. By this means the Indian cavalry, with the exception of a few men, was quite cut up in the action; as was also the infantry, since the Macedonians were now pressing upon them from all sides. Upon this, all who could do so turned to flight through the spaces which intervened between the parts of Alexander's cavalry.

CHAPTER XVIII. LOSSES OF THE COMBATANTS.  PORUS SURRENDERS.
At the same time Craterus and the other officers of Alexander's army who had been left behind on the bank of the Hydaspes crossed the river, when they perceived that Alexander was winning a brilliant victory. These men, being fresh, followed up the pursuit instead of Alexander's exhausted troops, and made no less a slaughter of the Indians in their retreat. Of the Indians little short of 20,000 infantry and 3,000 cavalry were killed in this battle. All their chariots were broken to pieces; and two sons of Porus were slain, as were also Spitaces, the governor of the district, the leaders of the elephants and of the chariots, and all the cavalry officers and generals of Porus's army. All the elephants which were not killed there, were captured. Of Alexander's forces, about 80 of the 6,000 foot-soldiers who were engaged in the first attack were killed; 10 of the horse-archers, who were also the first to engage in the action; about 20 of the Companion cavalry, and about 200 of the other horsemen fell. When Porus, who exhibited great talent in the battle, performing the deeds not only of a general but also of a valiant soldier, observed the slaughter of his cavalry, and some of his elephants lying dead, others destitute of keepers straying about in a forlorn condition, while most of his infantry had perished, he did not depart as Darius the Great King did, setting an example of flight to his men; but as long as any body of Indians remained compact in the battle, he kept up the struggle. But at last, having received a wound on the right shoulder, which part of his body alone was unprotected during the battle, he wheeled round. His body-armour (thorax) warded off the missiles from the rest of his body, being extraordinary both for its strength and the close fitting of its joints, as it was afterwards possible for those who saw him to observe. Then indeed he turned his elephant round and began to retire. Alexander, having seen that he was a great man and valiant in the battle, was very desirous of saving his life. He accordingly sent first to him Taxiles the Indian; who rode up as near to the elephant which was carrying Porus as seemed to him safe, and told him to stop the beast, assuring him that it was no longer possible for him to flee, and bidding him listen to Alexander's message. But when he saw his old foe Taxiles, he wheeled round and was preparing to strike him with a javelin; and perhaps he would have killed him, if he had not quickly driven his horse forward out of the reach of Porus before he could strike him. But not even on this account was Alexander angry with Porus; but he kept on sending others in succession; and last of all Meroës an Indian, because he ascertained that he was an old friend of Porus. As soon as the latter heard the message brought to him by Meroës, being at the same time overcome by thirst, he stopped his elephant and dismounted from it. After he had drunk some water and felt refreshed, he ordered Meroës to lead him without delay to Alexander; and Meroës led him thither.

CHAPTER XIX. ALLIANCE WITH PORUS.
When Alexander heard that Meroës was bringing Porus to him, he rode in front of the line with a few of the Companions to meet Porus; and stopping his horse, he admired his handsome figure and his stature, which reached somewhat above five cubits. He was also surprised that he did not seem to be cowed in spirit, but advanced to meet him as one brave man would meet another brave man, after having gallantly struggled in defence of his own kingdom against another king. Then indeed Alexander was the first to speak, bidding him say what treatment he would like to receive. The story goes that Porus replied: "Treat me, O Alexander, like a king!" Alexander being pleased at the expression, said: "For my own sake, Porus, you shall be treated so; but for your own sake, ask me what is pleasing to you!" But Porus said that everything was included in that. Alexander, being still more pleased at this remark, not only granted him the rule over his own Indians, but also added another country to that which he had before, of larger extent than the former. Thus he treated the brave man in a kingly way, and from that time found him faithful in all things. Such was the result of Alexander's battle with Porus and the Indians living beyond the river Hydaspes, which was fought in the archonship of Hegemon at Athens, in the month of Mounichion.

Note: The archonship – the annual magistracy by which Athenian years were reckoned – of Hegemon was in the years 327-326 BC, and the month given corresponds to mid-April to mid-May, 326.

[Duncan Head]

Note that in the above I have used the following translations of military terms:

•   "Cavalry regiment" translates the Greek "hipparchia".
•   "Battalion" translates "taxis".
•   "Squadron" translates "ile".

[Mark G]

Could we retrospectively do this for the earlier battle days?

[Duncan Head]

Could we retrospectively do this for the earlier battle days?

We've already got Plataea and Chalons, I think. Any of the others - not a bad idea, but I'm not volunteering!

[Dave Beatty]

The Battle of the Hydaspes 326 BC Warrior Lists and Battle Notes.

My local group will wargame Hydaspes using WARRIOR rules and 2500 point armies in conjunction with the 2015 Society of Ancients Battle Day at GUARDIAN GAMES, 345 SE Taylor St, Portland, Oregon on 28 March from 5PM to 10PM.  There will be plenty of commands for anyone who cares to show up and we will be in the back room so the Portland craft beer will be flowing freely!

Fought in early July 326 BC between the Macedonian army of Alexander the Great and the Indian army of Porus.

Good articles in Slingshot 297 about each army.

Excellent post by Duncan Head on the SOA forum with a good translation of Arrian's description.

http://www.slitherine.com/forum/viewtopic.php?t=6788 – this has an excellent wargamer OB albeit for FOG (uses Immortal Fire lists on p41 for Alex and p32 for Porus).

http://thesecondachilles.com/2014/08/10/the-battle-of-the-hydaspes-river/ - paraphrase of Diodorus' account.

http://www.ancientbattles.com/WAB_Macedonians/Hydaspes2.htm - also of interest.

Major-General JFC Fuller's The Generalship of Alexander the Great (1960) is perhaps the best modern description of the battle (and my favorite) but differs somewhat from Tarn (1948).  Robin Lane Fox's Alexander the Great (1973), Peter Green's Alexander of Macedon (1991), and NGL Hammond's The Genius of Alexander the Great (1997) are all excellent sources.

PORUS – EARLY INDIAN, Oriental Warrior (OW) list #7;  DBA 2.2 list II/3, Classical Indian

Jonas' article in SS 297 compares well with Fuller/Arrian:

Modeling with 100 infantry/cavalry per figure, 15 elephants or chariots per figure.

Elephants             180 = 13 + 3 left at the river crossing facing Craterus (incl. Porus)
Chariots                     180 to 300 = 20 (including 120 = 8 in recce force)
Cavalry                      3600 to 4000 = 36 to 40 figures
Guards infantry           3000 = 30 figures
Hereditary infantry   12000 = 120 figures
Mercenary infantry   4000 = 40 figures
Elephant escorts           2000 = 20 figures
Militia infantry           7500 = 75 figures
Wild tribes              1500 = 15 figures

This very nearly fits into the Warrior OW 7 list with 5 commands and 2500 points (list attached). 

Some notes of explanation to the attached spreadsheets: TR = training (Regular or Irregular); CL = class (A through E); TYP = unit type; WPN = weapons; SIZ = # of elements of that type; ECO = cost per element; CCO = command cost; UCO = unit cost.

The five Indian commands will be: 
   Covering Force under Porus' son – force marched to table center (suffer 2 fatigue)
   Left wing
   Center (Porus)
   Right wing
   River crossing guard

This is a modification of the OW list – downgraded all foot to D, added a maiden guard LI unit to the river force, and I think I am over on the chariot runners.  In addition, only Indian generals will use 4 horse heavy chariots (since that is all I own– the rest of the Indian chariots will be 2 horse).

Macedonians - Alexander the Great – ALEXANDRIAN IMPERIAL, Classical Warrior # 23, DBA 2.2 list II/15, Alexandrian Imperial.

After JFC Fuller

Holding Force – Craterus
    Companion Cavalry – Craterus' Hipparchy         1000   9 figures
    Arachosian Cavalry                                     1000   12 figures
    Parapamisadae Cavalry                          1000   12 figures
    Phalanx Taxeis  –    Alcetas                               1500   16 figures
                         Polyperchon                                 1500   16 figures
   Asiatic Light Foot                                     1000   12 figures
   Artillery                                                             4 models
   Allied Indians – Taxiles   
         Indian Cavalry                                500   6 figures
         Indian Light Foot                                    1000   14 figures
         Indian Medium Foot (half JLS, half B)            3500   32 figures
         Indian elephants                                        20    1 figure            

Turning Force – Alexander
Aegema Royal Squadron                                    300   6 figures
Companion Cavalry Hipparchies
   Hephaestion                                             1000   9 figures
        Perdiccas                                             1000   9 figures
        Coenus                                                     1000   9 figures
        Demetrius                                             1000   9 figures
Dahae Horse Archers                                     1000   12 figures
Hypaspists – 2 units                                      3000   32 figures
Phalanx Taxeis   Antigenes                                1500   16 figures
                 Cleitus                                   1500   16 figures
Agrianians – javelins                                      1000   12 figures
Archers – two units of Cretans & Rhodians             2000   24 figures
Javelinmen                                                 1000   12 figures

Turning Force – Rear Group – Meleager
Phalanx Taxeis   Meleager                               1500   16 figures
            Attalus                                   1500   16 figures
            Gorgias                                       1500   16 figures
Greek Mercenary    Peltasts                                500   8 figures
                    Cavalry                                500   6 figures

In order to enable Alexander's unit to charge under the rules, he has been given an additional element of 3 figures.  In order to keep the Macedonian total close to 2500 points, the allied Indian foot is Irr D vice Irr C as called for in the list and the minimum of 2 elephants has been ignored.  Two Macedonian lists are included in the attached spreadsheet in order to take into account an alternate view of the number of Macedonian cavalry present (Hammond – that each hipparchia was only 500 or 6 figures strong).

The five Macedonian commands will be:

Turning Force – Alexander's
Turning Force Rear Group 1 – Meleager
Turning Force Rear Group 2 – Antigenes
Holding Force – Craterus
Holding Force – Allied Indians – Taxiles

THE BATTLEFIELD (After Stein 1931 and discussed in Fuller)

- The game will be played on a 4 foot by 8 foot table oriented east-west with a Major Water Feature on the north side.   
- Marshes and bogs will extend adjacent to the Hydaspes River from 12" from the Indian rear table edge to the Macedonian rear table edge with 2 element gaps between features on the Indian table half.  The marshes and bogs will be solid along the Macedonian table half. 
- No other terrain is used.
- Both armies will be deployed in accordance with Arrian's description (V, xv, 5-7).
- The Indian camp will be deployed in the center of the Indian rear zone. 
- The Macedonian camp is considered off table beyond the Hydaspes.
- Alexander's command will be marshaled in the rear zone of the east side. 
- Meleager's and Antigenes' commands will arrive sequentially in order of march, on Turn 1 if able, subsequent turns if not.
- The Indian covering force will marshal at the table centerline and that entire command will suffer 2 fatigue for having force marched. 
- The remainder of the Indian force (less the river crossing guard command) will marshal in the Indian rear zone facing the Macedonians. 
- The Indian river guard command will deploy in the Indian rear zone facing the Hydaspes.
- The two Macedonian commands listed in the Holding Force are off table across the Hydaspes on a Flank March. 

ADDITIONAL SCENARIO SPECIFIC RULES: 

- Character of all generals is diced for normally except no Macedonian general may be UNRELIABLE.
- All Indian commands are initially under HOLD orders.  Orders may be changed in accordance with the normal procedures at 4.4.
- The Macedonian CINC may assign orders to his commands as he sees fit (may I suggest ATTACK?). 
- To simulate the battle between the Indian covering force under Porus' son and Alexander, the Indian main body cannot move the first turn, and then can only make approaches for the rest of the game (only the Macedonian army can march).   Indian units may approach even if there is not a Macedonian unit within 480 paces (this is an exception to 6.13).
- The Macedonians automatically have the initiative on the first bound. 
- The artillery with Craterus will be mounted on rafts.  Craterus will have one raft per artillery model and will be allowed to begin landing one unit per raft per turn after rolling a successful flank march (5 or 6) in accordance with 14.45.  Disembarking a unit takes an entire approach move.  Units may not re-embark.  Artillery may not disembark.
- In order to accommodate the somewhat unusual 9 figure Macedonian cavalry units in the preferred list (and to better reflect their combat capability at Hydaspes), we will use another Macedonian cavalry rule in addition to the Special Rules on page 4 of Classical Warrior:
        5.  A second rank of Macedonian HC fights at full effect if charging, counter-charging or pursuing.  A third rank of Macedonian HC fights at half effect if charging, counter-charging or pursuing.  This is an exception to Warrior 9.23.

[Dave Beatty]

Oops, here are the army lists.

[Duncan Head]

That looks interesting, Dave.

But wouldn't it have been better in one of the Battleday threads rather than the History > Battles one?

[Dave Beatty]

That looks interesting, Dave.

But wouldn't it have been better in one of the Battleday threads rather than the History > Battles one?

Right you are Duncan!  I'll drop it over there.  Your "Hydaspes BattleDay" line threw me and I did not notice the thread title...