There was a man of the necessary recklessness. Leosthenes the Athenian had seen his father truckle to Macedonia, and in exile accept estates near Pella; himself, he did not agree, and so he had served as a mercenary captain and emerged in maturity as Macedonia's opponent. In July 324 he had been elected as one of Athens's ten generals for the year; when he took up office, Alexander had ordered his satraps to disband their mercenary armies, and in the autumn of 324 and the spring of 323 fugitive soldiers began to congregate along the Asian coast. The numbers were not large, no more than 8,000 or so, but Leosthenes saw them as an opportunity: Persian admirals and high officials, who had escaped Alexander's fleet nine years before, were still roaming free, prepared to accompany troops to Greece. Chares and Autophradates, both heroes of the war begun by Memnon in the Aegean, were waiting to take revenge, and Chares had used troops disbanded by satraps to good effect before. If he shipped them to the tip of southern Greece, a well-known mercenary base, Leosthenes could maintain them for Athens through his former professional contacts. Alexander was still in danger of the same piratical leaders as in the years when his invasion had begun.

The attempt was hazardous and not generally approved. Athens could call on a possible fleet of more than 300 ships, but she could never finance them, as Harpalus had already been turned from the city with his money and his troops before Leosthenes took up office: he was a lost hope, for news soon came that he had been murdered in Crete by a Spartan on his staff and that his troops were planning to raid North Africa rather than return. So Athens was left with little of the money she had long been needing, the prospect of some 8,000 mercenaries also needing pay, an unmanned fleet in dry dock, and a grievance in Samos which she dearly wished to settle. Leosdienes's plans to hire mercenaries had already been seen to fail the Spartan king Agis; even after Alexander's death they never added more than 5,000 troops to the city's resources. In Alexander's lifetime, the prospects were less enticing, for a huge Levantine fleet was at his disposal and all the while the Silver Shields and other Macedonian veterans were marching west from Opis, in slow stages, dangerously close to the coast and a fast boat home.

While Lcosthenes was left to scheme in the background, one more embassy set out in autumn to plead for Samos to be exempted from its exiles' return; wisely, Athens's assembly had realized that she must try every outlet before risking a forlorn revolt. As the ambassadors travelled, Alexander was riding south by chariot from Luristan's nomads, down towards Babylon, habitual winter residence of the Persian kings and scene seven years before of the most triumphant welcome of his career. Then, in the first flush of victory, he had ordered its holy temple of E-sagila to be restored, along with the steep-stepped ziggurat of Etemenanki. But the priests of Babylon had preferred their own finances, for as long as the temples were incomplete, they could spend the income from sacred land on more congenial goods than sacrifice and silver-polish, and they had delayed the building plans to suit themselves. If Alexander entered the city, he would angrily hurry them and so they came towards the Tigris to stop him.

Well versed in astrology, they deterred him with a prophecy. Their god, they said, advised him on no account to enter Babylon from the west; some said Alexander scorned them, but Aristobulus, who was placed to know better, insisted that he made a careful detour of the Euphrates, trying to avoid the western quarters of the city, until he was halted by the local marshes. The priests, no doubt, had known this, and by warning him against the western approaches, had hoped to exclude him from the city altogether. While Alexander respected the warnings of the gods, he would not submit to the trick of their anxious ministers; he marched in defiance through the western gate, and within days earth was being moved for the temple's new foundations. Tithes were to be collected once more from temple properties, a useful addition to the royal treasury.

Inside Babylon, as winter took hold, Alexander continued in his mood of bold decision. Nearchus and the explorers reported on their discoveries in the Persian Gulf, including the islands of Bahrein and Failaka which Alexander named after the Greek hero Icarus, and told of prospects for the voyage against Arabia. Despite the explorers' failure to round Arabia, a harbour was ordered to be dug at Babylon with boat-houses for a thousand ships, far the largest fleet that had ever been countenanced in Alexander's world and a force which lent plausibility to rumours that after Arabia, it would be Africa or the West. This fleet was not all. While cypresses were felled in the countryside to meet this remarkable demand, recruiting officers went east to Syria and Phoenicia 'to hire or buy men used to the sea, for Alexander intended to colonize the shore of the Persian Gulf, as he thought it would be no less prosperous than Phoenicia itself. Traders and messengers of the future would pass this new Phoenicia on their reopened route from India and put in for stores at these new harbour towns; the settlers too, would be sailors, able to follow the spring winds east to the Indus or strike out south for Arabia's spices and the newly conquered skeikdoms of the Hadramut. It was a far-sighted plan. Alexander's energy had all too plainly not deserted him, nor had the ruthlessness with which he and Philip had always transplanted settlements. But behind the order for the thousand ships lurked the officers' suspicion that Africa would follow Arabia and they would be made to sail round the south of the world.

When spring broke, he was quickly to work once more. Babylonian life had always depended on its intricate system of canals, and as Alexander sailed down the Euphrates to inspect the sites for his harbour and new settlements, he became aware that the irrigation was needlessly blocked, 'despite three months' work by ten thousand Assyrians to improve it'. Noticing a stretch of stony ground, he devised a simpler diversion for the river's overflow, and replaced the labours of 10,000 workmen by a single observation; then, sailing downstream, he explored the marshes at the mouth of the Euphrates and adorned, characteristically, the neglected tombs of its former kings and controllers. A site by the sea seemed to invite another Alexandria, so he ordered sufficient Greek mercenaries and disabled veterans to be selected as citizenry; but as he rowed back from his new creation, 'steering the boat in person', he suffered a slight misadventure: part of his fleet had lost the way, whereupon a sudden breeze blew off his royal hat, complete with diadem, and caught it in a clump of reeds. An unknown sailor swam away to retrieve it, and imprudently put the hat on his head as soon as he had disentangled it; his reward was a talent, but some said he was beheaded at the advice of the prophets before he could enjoy it, others, more plausibly, that he was scourged. All agreed he had sinned by assuming the diadem, already so powerful a symbol of royalty, and soon his rashness seemed itself to be an omen.

Back in Babylon, the flow of plans continued unabated and this time they touched on the army's final shape. Disbanded mercenaries from western Asia had arrived for service at the empire's centre, along with 20,ooo native Persians and a group of nomads. The Persians were brought by Peucestas their satrap; all of them were archers and javelin-throwers, light-armed recruits, therefore, from the province with most cause to prove hostile in all Asia, but Alexander enrolled them into his Macedonian brigades, where their files were headed front and rear by highly paid Macedonian veterans. It was the climax of his integration in the army: apart from his Iranian Successors, Companions and cavalry, his Foot Companions were now to be doubled in strength, and Persians outnumbered Macedonians by three to one. For four years already the Foot Companions had fought in more open order without their sarissas; possibly, at the last the Macedonians in front and rear were returned to their famous weapon, while light-armed Persians were to shoot arrows or javelins over their heads. First, a long-range volley from the Iranians' composite bows of horn and leather in the centre; then, an advance with three rows of eighteen-foot spears, backed by a core of light-armed troops for impetus. There was sense, as well as magnanimity, in a mixed Perso-Macedonian phalanx, for it put the middle ranks to more varied use.