His admiral Nearchus, held up meanwhile at the Indus, has left a brief explanation.

It was not that Alexander was ignorant of the difficulties of the journey, but he had heard that nobody yet who had passed that way had come through safely with an army; Queen Semiramis, on her return from India, had only brought back twenty survivors, King Cyrus a mere seven. These rumours inspired Alexander with a wish to rival Cyrus and Semiramis: at the same time, he wished to be near to his fleet and keep it supplied with what it needed.

The desert tribes had sent envoys to surrender five years earlier and the difficulties of their land were indeed familiar. But no known legend already linked Semiramis, heroic queen of Babylon, with such a desert march. Her only local memorial was the 'hill of Semiramis' at the far end of the journey, where Alexander and Nearchus remet. By then the troops had suffered appallingly and any excuse was welcome. Semiramis's name greeted the survivors, so she could be said, for solace, to have gone through the desert too; 'only twenty', said the officers, had managed it, whereas Alexander had 'saved' thousands. Bagoas and other Persians could add a similar story of Cyrus. When he set out, neither precedent was needed nor suggested by the landscape. The adventure's difficulties attracted him and his men, as always. Mishaps of other kings were only invented at the end. But it was the fleet which kept him down on his fateful route.

As he founded another Alexandria on the river Maxates, site of one of the old trading towns on the Bcluchistan desert, there were two available lines of advance to the west. Like Tamurlane or Babur after him, he could keep away from the shore of the Persian Gulf and head north-west where the river Porali waters the fertile Welpat pocket; he would reach the site of modem Bela, from where a rough road skirts the southern coastal hills and runs due west to Kirman through a countryside of cliff and sand, made tolerable by drifts of dates and grain-fields. A safe passage here would be rivalry enough of the legendary feats of Cyrus and Semiramis, but throughout, he would be blocked from the shore by a chain of mountains, and at a distance of a hundred miles, he could not liaise with the fleet or dig wells for its convenience. Hence he must have begun by intending to take the road to the south of the hills and seldom stray more than twenty miles from the sea until he reached Gwadar. His plan, after all, depended on linking the fleet and the army; the Gcdrosians, people of Makran, had sent word of their surrender as far back as autumn 330, so resistance, at worst, would be tribal.

The plan itself was eminently worthwhile. Supported by land, the fleet would sail westwards from the Indus to the Persian Gulf and thence to the coast of Babylonia; a waterway was to the ancient world what a railway, relatively, was to nineteenth-century Europe, and if Alexander's fleet succeeded in its navigation, it would have reopened the fastest available route between Asia and India. Not that its speed would ever be predictable. With a following wind, the journey westwards took at least six weeks: a return to India would only be possible in spring, when the trade monsoon changed direction. But if its value for messages and strategy was limited, as a trade route it had risks and possibilities for the patient sailor. In India, Alexander had discovered luxuries and raw materials which the courts of Asia would gladly put to use, and throughout history it is luxuries which have driven merchants down their most spectacular 388 routes. His prospectors had found gold and silver and mounds of salt; his troops had picked stones as precious as jasper and onyx from the rivers they had been asked to cross. There was ivory, horn, muslin and bales of cotton ready for the picking; Indian dogs and elephants were valuable cargo. Above all, there were the spices, the nards and cassia, cardamom, balsam and myrrh, sweet rush, resinous bdellium, and the putchuk which grew in the Punjab and the Indus delta.

The list of spices known to the Greeks after Alexander's death was five times more varied than before. For medicines and cooking, scents, fumigants and soaps, a wide range of spices was a rich man's delight, and though trade between India and Asia would be a hazardous and slow business, better left to foreign entrepreneurs, in spices alone there were imports enough to give it appeal. So much the cheaper if they could come by sea; only a priceless luxury has the value to reward a trader who runs such a risk over such a distance.

To this end, Alexander's plans were ambitious: he requested his admirals to keep close to the coastline and inspect every likely harbour, water-supply or stretch of fertile land; he had hopes of colonizing the shore and easing the journey for future sailors, but even here he had been anticipated; exploration of the Indian Ocean and the Persian Gulf was not the new idea that it seemed. For the past two thousand years, traders had been sailing west to Babylon from the Indian Ocean and towns had once flourished on the coastal rivers of Makran; the Persian kings had inherited the tradition and two hundred years before Alexander, Darius I had settled Greek and Carian sailors at the mouth of the Euphrates to expedite the naval routes which met there from the east. When the grand Persian palace was built at Susa, sissoo-wood had been shipped from the Punjab for its pillars, down the very sea route which Alexander now planned to investigate. As at the Indus, he was unaware that Scylax the sea captain had sailed two hundred years before and proved the truth of a long used tradeway to his enterprising Persian patron.

For the sake of an ancient sea route, therefore, he chose to march close to the shore. According to his admiral, 'he was not ignorant of the difficulty of the route'. Five years before, he had received ambassadors from the Gedrosians, men of Makran, who promised surrender, but this understatement leaves the extent of his knowledge unclear. By marching by this southern road he was attempting the most abominable route in all Asia. No comparable army has ever tried it since and its few explorers have suffered so bitterly that they have doubted whether Alexander could ever have preceded them unless the Makran desert had been friendlier in his day than theirs. But his intended coastal march cannot be argued away. As for the desert, even though it had supported towns on its coastal rivers two thousand years before, geology suggests that it had never been mild. His officers described it as 'less fiery than India's heat' but they could give no such credit to its sand dunes or its sterility. 'Alexander was not ignorant of the difficulty. ...' The march through Makran can only by understood by an explorer, for in the same mood, men have tried to climb the steepest face of Everest at the wrong season of the year or to conquer the North Pole in the inadequate care of a hot air balloon. There is a streak in man which drives him to dare what others have not thought possible, and Alexander had never believed in impossibilities anyway. Makran was the ambition of men who wished to set a record and had nothing left to conquer but a landscape which Persia had left alone. The route was not merely difficult; it was the most hellish march that Alexander could possibly have chosen. But nobody opposed it.

There are hints that he knew this more or less to be so. Some two months before, when approaching Pattala down the Indus, he had already detached all the Macedonian veterans whom he meant to discharge, probably some ten thousand in number, and had sent them together with two brigades of mercenaries and all the elephants west towards the foot of the Hindu Kush, from where they could follow the gentle lushness of the Helmand valley and reach the centre of the Empire without being troubled by desert. The Makran journey, therefore, was known to be a severe test, but for the rest of the army, there were consolations which may perhaps show local knowledge. They had been busied between Pattala and Karachi until early August; they would not toil over the sand-dunes of Makran until September, by which time the brief but regular rains could fairly be expected to fall in the hills and run down towards the coast. If Makran has a favourable season, it is perhaps late autumn; its coastline, for example, is a prolific home of the sweet-scented calotrope ( Calolropis procera ), which sheds its highly poisonous seeds from June to early September. The hot summer wind blows them into the face of summer travellers, who have suffered accordingly; by entering Makran in mid-September, Alexander would at least avoid disheartening wind and poison.