city: like King Cyrus, the Persian conqueror of Babylon, Alexander may also have chosen his first governor as a man with native connections, for both of Mazaeus's sons had been named after Bel, the primary god of Babylon. Perhaps he had married a Babylonian.

In similar mood Alexander gave the satrapy of Armenia to Mithrines, the Iranian who had surrendered Sardis three years earlier, and reinstated the Persian fortress commander in Babylon; he thus marked out a future theme in his empire, for Persian satraps who surrendered could now expect to be returned to provinces where they had ruled for Darius, but, as in Egypt or Caria, a Macedonian general would be set beside them to keep the local troops in loyal hands. This bargain would encourage surrender and save unnecessary problems of language and organization; the same Persian servants would be re-employed where possible and in the face of an empire, so much for the slogan of punishment and Greek revenge.

Having made known his arrangements, Alexander relaxed inside Babylon for nearly five weeks. There was much to see in a city whose size had long been exaggerated by the Greeks: the huge double walls of brick and bitumen, twelve miles in circumference, the turreted Ishtar Gate with its enamelled plaques of animals, the sacred Ziggurat, built in seven storeys to a height of 270 feet, these were extraordinary sights and all would figure in the various later lists of the Wonders of the World. Between tall gaunt houses, built without windows for the sake of coolness, the city's main highways ran in near-straight lines, their ground plan broken only by the curving course of the river Euphrates, bridged by a famous viaduct of stone. To a Greek, the city was built on an unimagined scale and its government quarters which rambled between the Ishtar Gate and the river Euphrates were no less astonishing: Alexander took up residence in the more southerly of the two palaces, a maze of some six hundred rooms whose four main reception chambers met in a throne-room and main court, built by Nebuchadnezzar to proportions which would not disgrace a Mantuan duke or Venetian doge. From the palace, he visited the northern fortress where Nebuchadnezzar had once kept his treasures and laid out his works of art as if in a museum, 'for the inspection of all people'; these, perhaps, Alexander saw as Persian property, 'while he admired the treasures and furniture of King Darius'. A vast mass of bullion completed his reward, enough to end all problems of finance in his career; never before had coins been used in Babylon, but a new mint was to help to convert the solid ingots to a form which the troops could use.

Riches were not the only concern. Around the palace buildings lay the Hanging Gardens, whose artificial terraces were so thickly planted with trees that they seemed to the Greeks, themselves mediocre gardeners, to be a forest suspended in the air; their cedars and spruces, it was said, had been transplanted by Nebuchadnezzar to comfort his Syrian queen for her homesickness in a bare and foreign land. Alexander took an interest in the terraced park and suggested that Greek plants should be introduced among the many Oriental trees; the wish was admirable, if none too fortunate, as only the ivies settled down in their new climate. The army's pleasures, meanwhile, were coarser: while Alexander surveyed his gardens, they made up for three years' dearth of women with the strip-tease artistes of the city brothels. Extremely generous pay from the city treasures encouraged them, a reward which may have been overdue.

Among the pleasures of Babylon it was tempting to forget that Alexander was still engaged in an unfinished war. Darius was still alive and no doubt preparing to rally in the mountains near Hamadan, but nothing was to be gained by pursuing him in winter through such rough and unfamiliar country, and the longer he was left, the more he might expose himself to another open encounter. The empire's palaces lay due east, full of treasure and ready for the taking; their capture would cut Darius off from his many surviving Persian supporters and leave him no choice except to retreat into ever more easterly deserts where his royalty might not go unchallenged. Tactically and financially, it made sound sense to continue to follow the Royal Road, and so in late November, Alexander set out towards it through country well stocked with the supplies which could not be amassed from central Iran in winter. His destination was Susa, administrative centre of the empire, and as he had sent a letter by courier to its satrap he was hoping for another surrender.

He had not gone far from Babylon before he met with a reminder of all that he left behind him. On the Royal Road he was greeted at last by the reinforcements which had been summoned the previous autumn from Greece: Macedonians, Greeks and some 4,000 Thracians known for savagery, they totalled nearly 15,000 and increased his strength by almost a third. In a famously well-stocked countryside, he stopped to arrange them. The infantry were distributed according to nationality, and a seventh brigade of Macedonians was added to the Foot Companions; in the cavalry, the squadrons were subdivided into platoons, and the platoon-commanders were chosen not for their race or their birth but for personal merit. These small units were more mobile and their divided commands were more trustworthy. In the same efficient spirit competitions were held, and the army's method of signalling was changed from a bugle to the Persian

method of a bonfire whose smoke would not be lost in the hubbub of a crowd.

These reinforcements' fate had been a strange one; they had been caught between emergencies before and behind them they had missed the battles where they could have been most use. They were too late for Gaugamela, and they had left Greece too soon to help Antipater out of the Spartan revolt which had at last come to a head; in the autumn of Gaugamela, 40,000 Macedonians and allies had marched to the hills near Megalopolis in southern Greece and challenged the Spartans and their mercenaries to a pitched battle, outnumbering them two to one. In fierce fighting, Agis the Spartan king had been killed and his rebels routed, but the credit belonged more to Antipater's allies, Greeks themselves, than to the relatively few Macedonians left under arms; Agis's rebellion had been heroic, but in true Spartan style it had come too late, and more Greeks had helped to suppress it than to join in a fight for freedom which Sparta had so often betrayed. To allies who knew of Sparta's past record, the cause of a Spartan king had had even less to recommend it than Alexander's own.

The reinforcements as yet knew nothing of the rebellion's outcome. They could only tell of danger in southern Greece, and it was an anxious Alexander who reviewed his new troops and continued to wait for a letter or sign from his contacts in Susa. Within days the satrap's son arrived to set his anxieties to rest. He offered to act as guide to the river Kara Su, known to the Greeks as the source of the Persian king's drinking water; there, his father was waiting with twelve Indian elephants and a herd of camels as proof of his friendship. Twenty days after leaving Babylon Alexander thus entered the province and palace of Susa in early December, at the end of the Royal Road which had determined his route for the past three years.

'Susa', wrote one of his fellow-officers, 'is fertile but scorchingly hot. At midday, the snakes and lizards cannot cross the city streets for fear of being burnt alive; when the people want a bath, they stand their water outdoors to heat it: if they leave barley spread out in the sun, it jumps as if it "were in an oven.' In early December the worst of the weather was over, but its effects were visible in the city's appearance: 'because of the heat, the houses are roofed with three feet of earth and built large, narrow and long; beams of the right size are scarce, but they use the palm-tree, which has a peculiar property: it is rigid, but when it ages it does not sag. Instead, the weight of the roof curves upwards, so that it gives much better support.' Even Babylon seemed preferable to such a climate.