Memnon's chances were to remain untested, for in June, while blockading the city of Mitylene, 'he fell ill and died, and this, if anything, harmed the King's affairs at that time'. It was a marvellous stroke of luck for Alexander, as there was no other Greek general with a knowledge of Macedonia, a long career in Persian service and a way with the hired Greeks under his command. Persia was soon to recognize it. The news of Memnon's death took some time to travel to Susa; the ponderous machinery of the Persian Empire was not to be lightly turned in a new direction, but such was the Great King's dismay at the loss of this one commander that as soon as he heard it in late June or July, he planned to alter the entire strategy of the war. Memnon could wish for no more telling epitaph than this change, but while the new plans were put into effect, events were to drift until late July giving Alexander scope for good fortune and Persia less chance of a quick recovery of face.

It is not certain when Alexander learnt of Memnon's death, but it could only have confirmed him in his business inland. Swinging eastwards along the Royal Road, he welcomed the token surrender of stray mountain tribes north of Ancyra whom the Persians had never troubled and whom Callisthenes could have identified by pleasing quotations and his comments on Homeric verse. Paphlagonia made its peace and was added to a western satrapy; then, the 50,000 troops followed their king along the edge of the salt desert, across the river Halys and on down the Royal Road, the smoothest surface for their supply wagons. Cappadocia is a desolate area, as grey and parched as some dead elephant's hide, and so Alexander put it under the control of an Oriental, probably a native; the North had been divided off by the Persians as an untamed kingdom, and although the centre and south fringed the Royal Road, Alexander did not waste time on securing it. The mountains remained more or less independent, a refuge for fugitive Persians, and thereafter an untamed pocket in the wars of Alexander's successors. Though populous, they were not particularly important.

Two weeks or so after crossing the river Halys, Alexander reached the south-cast border of Phrygia, where he would have hit upon the camp site used by Xenophon's soldiers in 401 B.C. From his readings of Xenophon's works, he could reason that he would shortly be faced by the defile of the Cilician Gates, 'impassable if obstructed by the enemy'. There are ways over the surrounding shoulders of the Golek-Boghaz hills which do avoid the extreme narrows of the pass, but Alexander decided to force it. Either he had made no reconnaissance, in the absence of native guides, or he reckoned that like Xenophon, he could scare the defenders into withdrawal. In this he was justified; the lightly armed units of archers, Shield Bearers and Agrianians were ordered to muster after dark, Alexander led them in person and by a night attack he so unnerved the local pass-guards that their satrap retreated, burning the crops behind him as he headed southwards to his capital at Tarsus. Relieved, Alexander marched the rest of his army through in safety.

On the far side of the pass, Alexander 'examined the position and is said to have marvelled at his own good fortune: he admitted that he could have been overwhelmed by boulders if there had been any defenders to roll them down on to his men. The road was barely wide enough for four abreast.' Happy in his entry into Cilicia, probably in late June, he descended into the 'large and well-watered plain beyond, full of various trees and vines' as Xenophon had found it, 'and abounding with sesame, millet, wheat and barley'. Enough would survive to satisfy the hungry troops as king and army hurried over the sixty odd miles to Tarsus, Callisthenes pointing out the sites of old Homeric cities in the neighbourhood which, no doubt to Alexander's excitement, had once been sacked by the spear of swift-footed Achilles.

Whatever Alexander himself may have said, the forcing of the Cilician Gates was not entirely due to his good fortune. Part of the reason lay, for once, where he could not see it: at the enemy court of the Persian king. In the royal palace at Susa there had been nothing smooth or Homeric about the progress of the months of June and July. They had begun with hopes that Memnon's good news would continue, that Alexander would be lured far into Asia and a confrontation would be avoided, while the land would be ravaged along his path, as Memnon had first suggested at the Granicus. This is exactly what the satrap at the Cilician gates had continued to do. In late June Alexander had entered Cilicia while Memnon's strategy was still in force, but by a cruel stroke, as his army passed unopposed through the defile, Memnon's death had become known at Susa and with it, the Great King had decided on more positive plans. By then, the narrows of the Cilician Gates had been wasted; Alexander had been invited through them for the sake of a policy which was now to be abandoned.

In late June or July, on hearing of Memnon's death, King Darius anxiously summoned a council of noble advisers. As Alexander bore down on distant Tarsus, word went round the court that tactics were under review. Honoured Friends and Royal Relatives, some honorific, others indeed

descended from the imperial harem, satraps and staff-bearers, Table Companions, Vitaxas, Benefactors of the King, Wearers of the Royal Purple, Chiliarchs of the Immortals, Orosangs and all the lesser Hazarapats foregathered in anxiety, knowing that at Susa their future was to be settled. In the council chamber, the assembled company paid obeisance to the superior presence of their king; opinions were expressed, points of strategy were mooted, but Darius's conviction that without Memnon he could no longer rely on war being shipped to the Balkans was generally agreed to be correct. A new move must be made against Alexander himself. The question for discussion was where a move would be most effective. The Athenian general Charidemus had joined the Persians after being exiled by Alexander and here he is said to have proposed that he himself should take 100,000 men, including 30,000 Greek mercenaries, and oppose Alexander alone. But Darius was unwilling to divide his army and was annoyed at the insolent remarks which Charidemus had added; he therefore 'seized him by the girdle according to the Persian custom and handed him over to his attendants for execution'. The story may have been dramatized by a patriotic Greek, but the central fact of their disagreement is probably true. Darius's reaction was to insist on summoning the fullest force and going to war in person. No renegade Athenian would dissuade him from his opinions; stewards, therefore, passed the word, scribes translated the details into Aramaic, couriers rode forth with their sealed letters; hyparchs and cparchs read, resigned themselves to the worst and left their district headquarters. Eyes and Ears of the king prowled round in search of stragglers, while the royal wives and imperial concubines dressed themselves for their customary attendance on a moving army and awaited their chariots and camels.

In the oppressive heat of July, Darius moved westwards to Babylon, a sweltering city with a low-lying palace which his ancestors had always tried to avoid in the height of summer. Sun and sand burnt alike but the Great King knew he had to hurry uncomfortably; already news would have arrived that Alexander had entered Cilicia, and within six weeks, he could be menacing Babylon's massive walls. There was too little time to call out the troops of the upper satrapies east and north-east of Hamadan to meet the emergency, but there was power enough within range. The two main horse-breeding grounds of the empire were still accessible, the Nisaean fields of the Medes with their famous acreage of lucerne, and the equally productive pastures of Armenia, reputed to send 20,000 horses each year as tribute. Armed riders could be sununoned from the king's colonists and local nobility; the problem was their supporting infantry, 156 for the only trained natives, apart from slingers and archers, were the famous palace guard of the 10,000 Immortals. They needed heavier allies, and there was no alternative but to weaken the sea-campaign in the Aegean by summoning most of the hired Greeks from the fleet.