Siege of Aornos

In the autumn of 327 BC, Alexander of Macedon stood on the banks of the Kabul River and divided his army. The main body, under his trusted general Hephaistion, would march south through the Khyber Pass toward the Indus. Alexander himself turned north, into the mountains. He had heard of a fortress so impregnable that legend held even the demigod Herakles had failed to take it. For a king who styled himself the son of Zeus and the heir of Herakles, this was not merely a military objective. It was a matter of destiny.

The fortress was called Aornos. The local Assakenoi tribe, a proud and warlike people whose territory stretched across the hills of modern Dir, Swat, and Buner, had already felt the fury of the Macedonian advance. At the battles of Bazira and Ora, now identified as Bir-Kot and Udegram, their resistance had crumbled. But their king, Karos, had led the survivors to a place he believed no army on earth could reach: a great plateau rising from the west bank of the Indus, its sides sheer as a cut stone, its summit broad enough to feed a thousand farming families.

The rock was Pir Sar, a long ridge at an elevation of some 2,200 metres above sea level, rising above the west bank of the Indus in what is today the Shangla district of Khyber Pakhtunkhwa. Its southern end overlooks the river directly. Its top is comparatively broad and flat, capable of supporting cultivation and a substantial population. On its northern end, where the ridge narrows to a neck, a deep ravine separates it from a separate, higher pinnacle called Bar Sar.

The Assakenoi defenders held the rock for weeks before Alexander's final assault

Alexander did not approach recklessly. He was, above all else, a strategist. He first dropped back down to the Kabul plain, rejoined his main army at Charsadda, and secured the region before turning his attention to Aornos. He established a logistical base at a town called Embolina, likely near modern Amb in Hazara, placing it under the command of Krateros, who was tasked with stockpiling grain and supplies for what might be a protracted siege.

Local men, offered a reward, came forward to guide the Greeks to a preliminary position from which an assault might be launched. Alexander selected a force of lightly armed troops under his general Ptolemy, the same man who would one day rule Egypt, and ordered him to seize a ridge position overlooking Pir Sar without being seen. The route was difficult but largely out of sight of the defenders. Ptolemy's men moved through the pine forests in silence, established themselves on the ridge-line called Chota Una, erected a palisade, dug a trench, and then lit a beacon fire to signal their success.

Ptolemy's secret flanking march through the pine forests to Chota Una

The next day, Alexander moved up with the main body. He chose a more direct route over the Pezal Kandao saddle but was spotted by the Assakenoi and driven back in a sharp fight. This allowed the defenders to turn their full attention on Ptolemy's small camp at Chota Una. Hard fighting continued throughout the day as the tribesmen tried to break through the palisade. Ptolemy held. At nightfall, using a trusted tribal deserter as messenger, Alexander sent a secret note to Ptolemy: he would attack again at dawn, and Ptolemy was to sally out from his position to strike the tribesmen from the rear.

At daybreak, Alexander came up the same route Ptolemy had used. The Assakenoi, fighting on two fronts, could not hold. By afternoon, the Greeks were firmly established on Una Sar. Pir Sar itself was now within reach, but the day was spent and the fighting died down at nightfall.

Macedonian engineers constructing the causeway across the ravine at Bar Sar

As the causeway grew, the psychological pressure on the defenders mounted. They could see the Greek siege engines being brought forward. They could hear the axes in the pine forests above them. After perhaps a week, the causeway was complete. Alexander ordered an early morning attack.

What happened next is told differently by the ancient sources. The most credible account comes from Arrian. He records that the Indians, seeing the end was near, sent out a herald ostensibly to discuss surrender terms, but in practice to buy time for the garrison to slip away. Alexander, perceiving this, agreed upon the times at which the withdrawal of sentries and the general evacuation of Pir Sar would begin. But once the tribal sentries had been pulled back, he himself, with seven hundred of his personal bodyguard, swarmed up Bar Sar and at a pre-arranged signal, charged down upon the retreating tribesmen. Caught by surprise, many were killed. Others, in their panic, threw themselves from the precipitous cliffs to their deaths below.

The final assault: Alexander and his bodyguard storm Bar Sar

On the summit of Aornos, Alexander made sacrifices to Minerva and Victory. He built a fort on the hill and entrusted it to Sisikottos, a trustworthy Indian who had served in his army. Then he turned south. By the middle of 326 BC, Alexander was across the Indus at Taxila. The conquest of Aornos, the rock that Herakles could not take, was complete.