Herodotus tells us that Cyaxares was the first to separate the lance-bearers, archers, and horsemen, and combine them into divisions; that is, he introduced a better and more manageable arrangement of the army. To the same prince, no doubt, is due the completion of the fortifications of Ecbatana, which we found had been strengthened by his predecessor Phraortes. When the fortifications were first begun, the place was merely intended as a point of defence against Assyria; but as soon as it became destined to aid in the maintenance of independence, it was necessary that it should be capable of offering refuge and support to the Median army, if hard pressed. The mountains of the Zagrus form the boundary wall, and at the same time the line of division between the Medes and Assyrians. As Polybius told us (p. 268), it was an ascent of twelve miles--_i.e._ four leagues--to the top of the pass. If the Medes failed to hold these passes, and were then defeated in their own table-land, the mountains of the Orontes formed a new point of protection to their retreat. The Orontes (Old Persian, _Urvanda_; now Elvend) is a steep range of mountains, traversing Media from north-west to south-east; the heights of the passes are given by travellers at 7000 or 10,000 feet; Ctesias puts the ascent at twenty-five stades;[492] recent explorers fix the time at four hours. On the eastern spur of this mountain wall, in a fertile plain, six leagues long and four leagues broad, lay Ecbatana, Old Persian _Hangmatana, i.e._ place of assembly, the Achmeta of the Hebrews. If the Orontes could not be held, the fortifications of Ecbatana formed a last point of protection for the Median army. From the Assyrians there was nothing more to be feared after the fall of Nineveh, but Cyaxares had no doubt felt, in the inundation of Media by the nomadic tribes of the Sacæ, and then in the final battles against Asshur, what a support was given by a strong metropolis; what good service the walls of Nineveh had rendered to the enemy, even in his decline. He saw what measures were being taken by Nebuchadnezzar, his step-son, to make his metropolis secure, and determined that the kingdom, which he had so rapidly and brilliantly erected and developed, should not be without the nucleus of an impregnable fortress and royal citadel. The booty in silver and gold, which the Medes gained in Nineveh, and of which we hear not in the Median poems only, but also from the Hebrew prophets who lived at the time of the fall of the city, provided no doubt ample means both for the erection of the strongest works, and for the adornment of these as well as the citadel.