Cophen campaign
The Cophen campaign was conducted by Alexander the Great in the Kabul Valley between May 327 BC and March 326 BC. It was conducted against the Aspasioi, the Guraeans, and the Assakenoi tribes in the Kunar Valley of Afghanistan, and Panjkora and Swat Valleys in what is now Khyber Pakhtunkhwa, Pakistan. The campaign's goal was to secure the Macedonian line of communications so that the Macedonian army could proceed into India properly.
Background
It had been Alexander's purpose to conquer the whole of the Persian Empire which extended as far as Gandhara. A previous king of the Persian Achaemenid Empire, Darius the Great, had sent one of his generals, Skylax, to sail down the Indus. Following this expedition, Darius was able to conquer the surrounding Indian territory and receive tribute of 350 Euboic talents per annum. Relatively little is known about the Punjab in Alexander's day. There were a variety of princelings and republics, which the Indians called, "kingless" peoples. All were vying for power over the region.The King of Taxila, Omphis, whom the Macedonians called "Taxila" after his capital city, had invited Alexander to come to his aid in his struggle against the neighbouring potentate Porus. Porus was considered to be the most powerful prince in the region. Another king, Shashigupta, had served in the Persian Army at Gaugumela and had later been Alexander's vassal. Alexander gained useful intelligence concerning the region from these individuals.
Alexander had begun planning the expedition two years before, in 329 BC, but had been delayed in carrying out the expedition by a series of revolts that had taken place in Aria, Sogdiana and Bactria. He was held up in putting down these revolts as he had been marching through the Hindu Kush mid-winter and decided to camp in the mountains. It was during this time that he founded the city of Alexandria ad Caucasum. This city was some twenty-five miles north-west of modern Kabul, in Afghanistan.
Returning to Alexandria ad Caucasum in May 327 BC he found a surfeit of victual and supplies ready for the army for its expedition into India. However, there were administrative matters that required his attention. Both the satrap of the Paropamisadae, Proëxes, and the commander of the garrison, Neiloxinus, were replaced due to their unsatisfactory conduct. When Alexander set out for Nicaea, it is said that he had 150,000 soldiers. Historians have expressed doubts about the veracity of these numbers. Alexander had in his army soldiers from Greece, Thrace and Agriania as well as soldiers from various territories within his new empire. Leaving Alexandria ad Caucasum, Alexander marched to Nicaea, where he sacrificed to Athena and exclaiming that he was following in the footsteps of his ancestor Heracles, began his advance towards the Indus along the Kabul River.
First phase—Aspasians
While on the march, Alexander sent ambassadors ahead to the various tribes that were ahead of him, ordering them to submit and provide him with hostages. Taxila and several other princes came to him bringing him gifts as proof of their vassalage and paying tribute with gifts for the Macedonians. Amongst the gifts that the Macedonians had never seen before, the Indian potentates furnished Alexander with 25 elephantsAs Alexander had now effectively replaced Darius III as King of Persia, Alexander was now effectively the new overlord of the Empire, including this easternmost region. Therefore, Alexander was able to treat anyone who resisted him as in revolt against him. While descending into the Cophen valley, Alexander informed his new vassals of his intentions. He planned to spend the rest of the summer and autumn reducing the region ahead of him up to the Indus river. From there, he was going to proceed beyond the Indus and punish the Indian states and tribes which had not recognised him as their overlord and had not sent him ambassadors with tribute.
However, he found that the campaign was far more difficult than he had anticipated. At Nicaea, he took the time to split his army into two separate forces with the object of retaining the interior lines so that he could reinforce his army at any point should any particular section of his army become threatened during the course of his campaign in the valley of the Cophen. In addition to this, these two forces were to keep the Indian rulers in the region from combining their forces and coordinating their efforts against the Macedonians.
The army that was to march along the river Cophen was to be commanded by Perdiccas and Hephaestion. They were accompanied by the king of Taxila to take advantage of his knowledge of the region. They were to proceed along the southern bank of the Cophen. They had at their disposal three brigades led by Gorgias, Clitus and Meleager, half the Companion and all the Greek mercenary cavalry. Their instructions were to follow the river to the Indus, bringing all the cities and fortifications to submission on the way through either systematic reduction or by terms. Then they were to build a bridge upon their arrival at the Indus so that when the King arrived and after the winter when Alexander had wintered his army in the region, they could proceed to cross the river and punish the tribes across the Indus.
Meanwhile, Alexander had at his disposal the bulk of the forces in his army. These forces comprised the shield bearing guards, four regiments of Companion cavalry, the Phalanx, the foot agema, the archers, the other half of the horse archers, the Agrianians and the horse lancers.
Alexander planned to march along all the valleys that were in between Nicaea and the river Indus intending to subdue those tribes that had not paid tribute.
Alexander received information that the Aśvaka, the first tribe whose lands he had entered, had retreated to their capital. Eager to defeat them, the Macedonians crossed a river with all the cavalry and eight hundred Macedonian infantry mounted on horses. They arrived quickly enough to kill a number of the Aspasians and drive them within their walls. The rest of the army came up the next day and took the city. However, a number of the Aspasians decided to flee before the city was taken, seeing their cause as lost. The Macedonians followed them and killed a great many of them. Alexander's men, enraged to see that their king had been injured during the course of the siege, razed the city to the ground. The Macedonians marched off to the next town, Andaca, which capitulated.
Alexander then left Craterus, whom he had probably kept in hand in case of just such an occasion, in command of a force responsible for gaining and keeping control of the tribes living in the surrounding valleys.
Alexander's next destination was Euspla, where the King of the Aspasians was based. At this point, deeming their cause lost, the Aspasians burned this city and fled. The Macedonians pursued them. During the ensuing combat, one of the Aspasians thrust his spear right through Ptolemy's breast plate, but the spear did not make contact with him due to the armour stopping the severity of the blow. It was at this point that Ptolemy killed the King of the Aspasians.
Second phase—Guraeans
After defeating the Aspasians and thus securing his lines of communication, the Macedonians marched towards the Guraean fortified city of Arigaeum. On hearing news of Alexander's capacity as a general and besieger, the populace razed the fortress. It was at this particular point that Craterus returned to Alexander after gaining control over the Aspasian valleys, including Andaca. Alexander ordered Craterus to set up several new colonies in the region, including Arigaeum. Control of Arigaeum and Andaca was important in controlling the Choaspes river, and occupying the fortresses with healthy garrisons would prove advantageous to Alexander in the case of revolts.The Guraeans had retreated after burning their fortified city, joined up with their fellow tribesmen and prepared themselves to face Alexander.
Siege of Arigaeum
Ptolemy, who had been sent ahead on a foraging expedition, came back to the main contingent of the army under Alexander and reported that there was a very large force assembled and preparing to face the Macedonians.When the Macedonians arrived where the assembled force had gathered, Alexander divided his army into three parts with Ptolemy taking up the left. Leonnatus was ordered to take up the right flank, with Attalus' and Balacrus' brigades. Alexander took up the centre opposed to the Guraean centre. Alexander sent Ptolemy and Leonnatus to their respective flanks by routes that the Guraeans could not observe, thus hiding these two particular flanks of his army from the Guraeans. Alexander's contingent was comparatively small, and he planned to lure them out and to fight them while Leonnatus and Ptolemy took their flanks.
As expected, the Guraeans attacked Alexander's small contingent, and after Ptolemy faced rough fighting, he was able to achieve victory on his flank. Leonnatus' victory was comparatively easier, after which time the enemy surrendered. It is said that 40,000 Guraeans were captured.