Menacing as this power of Urartu appeared at the end of the ninth century to an enfeebled Assyrian dynasty, there were two other racial groups, lately arrived on its horizon, which in the event would prove more really dangerous. One of these lay along the north-eastern frontier on the farther slopes of the Zagros mountains and on the plateau beyond. It was apparently a composite people which had been going through a slow process of formation and growth. One element in it seems to have been of the same blood as a strong pastoral population which was then ranging the steppes of southern Russia and west central Asia, and would come to be known vaguely to the earliest Greeks as Cimmerians, and scarcely less precisely to their descendants, as Scyths. Its name would be a household word in the East before long. A trans-Caucasian offshoot of this had settled in modern Azerbaijan, where for a long time past it had been receiving gradual reinforcements of eastern migrants, belonging to what is called the Iranian group of Aryans. Filtering through the passage between the Caspian range and the salt desert, which Teheran now guards, these Iranians spread out over north-west Persia and southwards into the well-watered country on the western edge of the plateau, overlooking the lowlands of the Tigris basin. Some part of them, under the name Parsua, seems to have settled down as far north as the western shores of Lake Urmia, on the edge of the Ararat kingdom; another part as far south as the borders of Elam. Between these extreme points the immigrants appear to have amalgamated with the settled Scyths, and in virtue of racial superiority to have become predominant partners in the combination. At some uncertain period--probably before 800 B.C.--there had arisen from the Iranian element an individual, Zoroaster, who converted his people from element-worship to a spiritual belief in personal divinity; and by this reform of cult both raised its social status and gave it political cohesion. The East began to know and fear the combination under the name _Manda_, and from Shalmaneser II onwards the Assyrian kings had to devote ever more attention to the Manda country, raiding it, sacking it, exacting tribute from it, but all the while betraying their growing consciousness that a grave peril lurked behind Zagros, the peril of the Medes. [Footnote: I venture to adhere throughout to the old identification of the _Manda_ power, which ultimately overthrew Assyria, with the _Medes_, in spite of high authorities who nowadays assume that the latter played no part in that overthrow, but have been introduced into this chapter of history by an erroneous identification made by Greeks. I cannot believe that both Greek and Hebrew authorities of very little later date both fell into such an error.] SECTION 4. THE CHALDAEANS