Against an Alexander, peace is a dangerous ambition. During his scouting, a bend had been noticed in the river, some seventeen miles upstream from Haranpur. The banks were thickly treed and on Alexander's side the headland of Mangal Dev rose to a height of 1,000 feet; a mile-long ditch ran beside it into the main riverbed, which seemed to be very narrow, partly because it was divided by an island. Remote and well-hidden, it was exactly what Alexander had been wanting. He could take a select force, leaving others to cause a diversion, hide in the scrub near Mangal Dev and slip across the river under cover of night. His recent manoeuvres had so lulled the Indians' suspicions that one more flurry would seem nothing unusual. Porus's guards were too few to stop him and by the time the

Rajah heard the news at base, his main force would be safely on dry land. This strategy would never have been considered had he not the highest confidence in his officers of staff. Some were to act as a decoy, others were to arrange the transport: all the while, the yellow waters of the Jhelum were rising and gathering speed.

On the night of the grand attack, fires were lit near Haranpur to suggest a permanent camp. The faithful Craterus, so often the second-in-command, was ordered to stay at base with more than a third of the army: he was briefed for each of two emergencies, depending on the conduct of the elephants.

If Porus fled, or took all his elephants up the bank towards Alexander's crossing-party, Craterus was to ford the river and attack the Indian camp opposite, however many troops had been left to guard it. But if Porus kept even a few of his elephants back where they now stood, Craterus was on no account to venture on to the river except in the case of a Macedonian victory.

There could be no more cautious tribute to the menace of an elephant in battle.

A few miles further up the bank, between Craterus at Haranpur and the crossing-point near Mangal Dev, the three mercenary commanders were posted with all their hired troops and ordered to brave the river only when the Indians were fully engaged. This engagement was to be the work of some 6,000 foot and 5,000 horse, chosen for their balance and experience. Shield Bearers, Agrianian javelin-men and archers would have little fear of the river and less of the elephants; their numbers imply that no Foot Companions were detailed to the front line. The cavalry, where Porus was weakest, were fundamental to the plan: the Royal Squadron and three brigades of the Companions would deliver their usual charge, thrusting-spears to the fore, while Scythians, mounted archers and the pick of the Iranian horse, probably armed with javelins, would first pin down the enemy at longer range. Alexander led the troops in person, accompanied by bodyguards and senior brigadiers: some said Ptolemy was left behind to raise a diversion, but Ptolemy himself insisted that he sailed with the leaders and fought as hard as the rest of them. It was not an adventure which a future Pharaoh would like to admit he had missed.

The preparations had been patient. Boats had been cut into sections and carted, presumably by night, to the chosen ford, where they were pieced together and hidden in the scrub, along with the usual rafts which were stitched from tent-skins and stuffed with hay. On the afternoon of the crossing, Alexander had looped back behind his lines as if in search of supplies, and led his troops by a roundabout route into the woodland near the Mangal Dev ford. There they were to wait and cross in the darkness. But nothing could be done to prepare the weather; in the early evening an electric summer storm broke overhead, thundering and hissing with rain so that even the Macedonian war cry would have been inaudible. The covering noise was not unwelcome, but the clouds blotted out any light from the stars and the men had to sit until the wind and rain subsided, whiling away the hours until dawn was perilously close. The river was racing faster than ever when Alexander launched out in a thirty-oared boat, showing his troops the way to what he believed to be dry land.

As he put in to the nearest bank he was sighted by Porus's pickets, who turned and galloped back across the seventeen miles of rough ground to their rajah at base. It seemed too simple to be true: they would not return for at least an hour and a half, by which time Alexander could have disembarked enough of his 11,000 men and 5,000 horses to repulse them. But in the aftermath of the storm, he had landed not on the far bank but on the island, deceptively placed in mid-stream. There was a ford across to dry land but the river had risen so fast that it was not easily detected, especially in a hurry: there was no time left to man the boats again and head for the shore. Alexander had to set his men an example. He urged Bucephalas down into the river and steadied the old horse as he felt for the reassuring clatter of a hard bed beneath and held his ground against water which now came up to his shoulder. Even when four or five have to clamber out of a river, it pays to be the first rider up the bank; when 5,000 horses are waiting their turn, latecomers can only dread the morass churned up by those in front. But they managed, even without stirrups, to steady themselves as the horses floundered. The infantry followed behind, up to their chests in water, all the more unpleasant for any who happened to be wearing breastplates.

Once on the far bank Alexander pressed ahead with his cavalry. This bold move was well planned. Any advance troops sent by Porus would be the very fastest in his army, no doubt the cavalry and chariots, for he would wish them to arrive before the Macedonians had crossed. In this aim they had failed, so the light Macedonian infantry were not needed to counter them. Alexander's horsemen outnumbered Porus's total cavalry, and chariots were no menace to veterans of Gaugamela, reinforced by mounted archers. If Porus decided to move his entire force at once, elephants included, it would be several hours before he appeared, and meanwhile the Macedonian infantry would have rejoined their king and the Companions, grateful for the cover they had been given.

Porus's retort, when it arrived, was variously described both in number and result. According to Ptolemy, who claimed to be present, 120 chariots and 2,000 horse came careering down the riverside only to run into a slanted wing of Companions and horse-archers, who attacked in squadrons and soon showed the Indians why they were the finest riders in the world. The chariots were of the fast four-horse variety, and they fell victim to muddy ground which the recent storm had made unusually slippery. Pelted by horse-archers, their teams careered with no respect for the reins, until the javelin-throwers on board found themselves struck in ditches off the beaten track. Those who could not reverse were wiped out, their general among them: some said he was Porus's son, others Porus's brother, but he died before revealing his identity. Alexander's cavalry had won a promising victory: they halted, the flanks of their horses still steaming from the rain, and when the infantry line overtook them, all 11,000 men could look forward to their next objective, Porus himself, some fifteen miles distant.

Porus's situation was unenviable but by no means hopeless. In mid-morning, he found himself threatened on two sides at once. Craterus was waiting to cross the river directly opposite, while Alexander had already crossed and was moving down the near bank, set on a pincer attack. Alexander, therefore, was his first priority, and he would do well to come far forward from base to meet him. Elephants and troops would have to be left to stop Craterus slipping across into the rear, but this division of his forces could ill be afforded. His cavalry was outnumbered, perhaps by three to one, and survivors of his advance party were talking dispiritedly of their defeat, for the Indians were practised horsemen, but in skills that now seemed irrelevant: