Aral Sea, served to fence off the approaches to Persia where they had always been most vulnerable, in the north-east, which previously had lain wide open to incursions from the steppes of Central Asia. Gandhara, Bactria and Sogdiana: these lands, once breeding-grounds of menace and instability, were now transformed into bulwarks of Persian might.
And bulwarks of much besides. Savages, as all civilised peoples were agreed, belonged exactly where Cyrus was pinning them, in the remote bleakness of the rim of the world. What might happen otherwise was still the stuff of nightmares. The Medes, for instance, preserved lurid folk-tales of how their empire, at the very peak of its might, had been subjected to the slant-eyed Saka, a notoriously brutal people, cruel and untamed like the steppes from which they came, who had held on to Media for twenty-eight years. There was great alarm, then, when Cyrus, advancing from Sogdiana into what is now Kazakhstan, found himself confronted by these same demons from the Median past, readily distinguishable by their high pointed caps and their alarming facility with axes. A leader of the Saka, captured by Cyrus and treated with notable chivalry, duly submitted to the invaders, and his people, taking service with the Persian king, soon established themselves as the most ferocious of the imperial troops. But this had been only a single tribe. Beyond its homeland lay further plains, bandit-haunted and drear, their immensity mocking all human ambition -even that of the greatest conqueror ever known. How far they stretched no one could say for sure, nor what might be found at their extremities: griffins, some claimed; and tribes of men with goats' feet; and frozen wastes, where the inhabitants hibernated for six months every year; and beyond them, surrounding the world, the great River Rangha, as wide as the most immense sea. 26 Cyrus, crossing the monotony of the steppelands, certainly had no intention of pushing that far; and when at length he found a broad river obstructing his path, he rested on its bank, and there, amid mudflats and the buzzing of mosquitoes, called a halt, at last, to his advance. The river itself, the Jaxartes, was shallow and island-dotted, affording only the barest of natural frontiers; so Cyrus, making good the deficiencies of nature, ordered the construction of seven frontier towns, naming the greatest one after himself— 'Cyropolis'. Henceforward, like a slave, the featureless savagery of the steppes was to wear the mark of the Persian king.
This branding of his identity upon the land of the Saka proclaimed an imperious dual message. No more would the untamed war-bands beyond the Jaxartes be permitted to raid southwards; and no more would those behind it have to fear for their security. Cyrus' strategy had always been to menace his enemies and to reassure his slaves —and by 540 bc , with the eastern frontier stabilised, he felt ready to put it to its ultimate test. Returning to the Zagros, he fixed his predatory gaze on that supreme goal of every conqueror's ambition, the wealthy flat-lands of what is now southern Iraq, stretching from Assyria to the Persian Gulf, the stage for splendid cities since the very dawn of time. No man could truly be hailed as the master of the world until he had subdued its ancient heartland — as Cyrus, the arriviste, was all too well aware. Yet he would also have known that its inhabitants were no backward frontiersmen, untutored in the propaganda of despots. Indeed, it was they who regarded the Persians as savages. Cyrus, a man who specialised in overturning hostile preconceptions, chose to meet this new challenge head on. Launching his invasion of enemy territory, he claimed to be defending it; leading an immense army, he affected to be an avatar of peace. And everywhere, strongholds met him with an opening of their gates.
In truth, Persian firepower being what it was, this had been the only sane policy for the defenders to adopt. The