From this point downwards we can date the union and independence of Media. Had the country been free and united at the time of Sargon, Sennacherib, and Esarhaddon, the rulers of Assyria would not have marched against Syria and Cilicia, or undertaken the conquest of Egypt. Assurbanipal could not have employed the forces of the kingdom to maintain Egypt, or reduce Babylon, or annihilate Edom, or make campaigns to the distant parts of Arabia, if the united power of Media had existed behind the Zagrus, close on the borders of his native land, the very centre of the Assyrian power. Still less could he have looked on in inaction, while Phraortes, as Herodotus tells us, conquered the Persians, and attacked one nation after another till he had subjugated Asia. On the other hand, the annihilation of Elam by Assurbanipal, and consequent strengthening of the Assyrian power on the borders of Persia, may well have determined the Persians to unite with the Medes, and accept a position under Phraortes. In considering the situation and importance of the powers, we may assume that Phraortes, in the first instance, thought rather of defence than of any attack on Assyria, and for this object undertook the fortification of Ecbatana on a large scale. What could have induced him to abandon the protecting line of the Zagrus, in order to attack under the massive walls of its metropolis the power which had just dealt such heavy and destructive blows on ancient states like Babylonia and Elam, unless we attribute to him the most reckless audacity? Nor, on the other hand, can we suppose that an ancient ruler like Assurbanipal, who had held his own successfully against the searching attack of his brother, and finally gained important conquests, would have allowed the formation of the Median power in the closest proximity, and its combination with the Persians, without the least attempt to prevent it. It was in repulsing this attack that Phraortes fell.[480]