Alexander was a young man yet, only twenty-six. It was four years since he had left Europe, and in that short time he had done wonders. He had conquered the whole western half of the Persian Empire. Now he resolutely turned his face to the unknown east and started forth on an expedition of exploration.

Following the main highway from Media, which to-day leads from Teheran, capital of modern Persia, into the land of the Turkomans and the borders of Russia, he found himself between the great salt desert and the mountains, which to-day mark the frontier of Persia. Suddenly, to his great surprise, the Caspian Sea came into sight. It seemed about the same size as the Black Sea, and he concluded it was connected with the Sea of Azof, though the men of his day were certain enough that it was the most northern of four great gulfs connected with the outer ocean which flowed round the world.

Onwards towards the east he marched with his great army. To conciliate the tribes through which he passed, he adopted Persian dress. This annoyed his Greek countrymen, but, "as they admired his other virtues, they thought he might be suffered to please himself a little and enjoy his vanity."

Arrived at the modern boundary between Persia, Afghanistan, and Russia, he and his men pushed on across Afghanistan, by the caravan route that had long existed from the shores of the Caspian, by modern Herat, Kandahar,1 which still bears the conqueror's name, and Kabul to India. Their way lay through deep snow, deeper than they had ever seen before; and by the time they had reached the mountains of Kabul it was midwinter.

1 Kandahar = Alexandria in a modern form.

Between Alexander and India still lay the lofty range of the Hindu Koosh or Indian Caucasus. But before going south toward India, he turned northwards to explore the unknown country which lay about the river Oxus. They found the Oxus, a mighty stream, swollen with melting snows. There were no boats and no wood to build them, so Alexander pioneered his men across in "life-preservers" made out of their leather tent coverings and stuffed with straw. This river impressed the Greeks even more than the Euphrates and Tigris, as it impressed many an explorer and poet since these early days. Let us recall Matthew Arnold's famous description of the Oxus, now seen for the first time by the Greeks.

"But the majestic river floated on,
Out of the mist and hum of that low land,
Into the frosty starlight, and there moved
· · · · ·
Brimming, and bright, and large; then sands begin
To hem his watery march and dam his streams,
And split his currents; that for many a league
The shorn and parcell'd Oxus strains along
Through beds of sand and matted rushy isles—
Oxus, forgetting the bright speed he had,
In his high mountain-cradle in Pamere,
A foil'd circuitous wanderer—till at last
The long'd for dash of waves is heard, and wide
His luminous home of waters opens, bright
And tranquil, from whose floor the new-bathed stars
Emerge, and shine upon the Aral Sea."

Here in this valley the Greeks met more determined opposition than they had yet encountered since entering Asia, and over two years were occupied in reducing this single district (now Bokhara and Turkestan) to submission, though it was only some three hundred and fifty miles square, and in one single year Alexander had conquered a kingdom over one thousand miles in width.

It was not till the spring of 327 B.C. that he was ready to cross the Hindu Koosh and begin the great expedition into India. The night before the start Alexander discovered that his troops were now so heavily laden with spoils that they were quite unfit for the long march. So in the early morning, when they were all ready to start, he suddenly set fire to his own baggage, and, giving orders that all his men were to do the same, the army started for the passes of the lofty mountain range. And—

"... as a troop of pedlars from Kabul
Cross underneath the Indian Caucasus,
That vast sky neighbouring mountain of milk snow;
Crossing so high, that, as they mount, they pass
Long flocks of travelling birds dead on the snow,
Choked by the air, and scarce can they themselves
Slake their parch'd throats with sugar'd mulberries—
In single file they move, and stop their breath,
For fear they should dislodge the o'erhanging snows."