To take the case of Babylon first.  It was no mere conglomeration of tribes, nor a state of minor importance, but an actual empire, nearly as large as that of Assyria itself, and almost as solidly welded together.  It extended from the Turnat and the mountains of Blam to the Arabian desert and the Nar-Marratutn, and even though the Cossaeans, Elamites, Kalda, Sumerians, Akkadians, and other remnants of ancient peoples who formed its somewhat motley population, had dwelt there for centuries in a state of chronic discord, they all agreed—­in theory, at any rate—­in recognising the common suzerainty of Babylon.  Babylon was, moreover, by general acknowledgment, the ancient metropolis to which Assyria owed its whole civilisation; it was the holy city whose gods and whose laws had served as a prototype for the gods and laws of Assyria; from its temples and its archives the Assyrian scribes had drawn such knowledge as they had of the history of the ancient world, their religious doctrines and ceremonies, their methods of interpreting the omens and of forecasting the future—­in short, their whole literature, both sacred and profane.  The King of Nineveh might conquer Babylon, might even enter within its gates in the hour of triumph, and, when once he had it at his mercy, might throw down its walls, demolish its palaces, destroy its ziggurat, burn its houses, exterminate or carry off its inhabitants, and blot out its name from the list of nations; but so long as he recoiled from the sacrilege involved in such irreparable destruction, he was not merely powerless to reduce it to the level of an ordinary leading provincial town, such as Tela or Tushkhan, but he could not even deprive it in any way of its rank as a capital, or hope to make it anything less than the second city of his empire.  As long as it remained in existence, it necessarily took precedence of all others, thanks to its extensive area, the beauty and antiquity of its buildings, and the number of its inhabitants.  The pride of its nobles and priests, subdued for a moment by defeat, would almost instantly have reasserted itself, had the victor sought to lower the dignity of their city; Babylon only consented to accept an alien master provided he bowed himself respectfully before its superiority, and was willing to forget that he was a stranger within its gates, and was ready to comply with its laws and masquerade as a Babylonian.  Tiglath-pileser III. never dreamt, therefore, of treating the Babylonians as slaves, or of subordinating them to their Assyrian descendants, but left their liberties and territory alike unimpaired.  He did not attempt to fuse into a single empire the two kingdoms which his ability had won for him; he kept them separate, and was content to be monarch of both on similar terms.  He divided himself, as it were, into two persons, one of whom reigned in Calah, while the other reigned in Karduniash, and his Chaldaean subjects took care to invest this dual role