The fact that under her West-Semitic kings Babylon should have taken rank as the capital city does not in itself account for her permanent enjoyment of that position. The earlier history of the lands of Sumer and Akkad abounds with similar examples of the sudden rise of cities, followed, after an interval of power, by their equally sudden relapse into comparative obscurity. The political centre of gravity was continually shifting from one town to another, and the problem we have to solve is why, having come to rest in Babylon, it should have remained there. To the Western Semites themselves, after a political existence of three centuries, it must have seemed that their city was about to share the fate of her numerous predecessors. When the Hittite raiders captured and sacked Babylon and carried off her patron deities, events must have appeared to be taking their normal course. After the country, with her abounding fertility, had been given time to recover from her temporary depression, she might have been expected to emerge once more, according to precedent, under the aegis of some other city. Yet it was within the ancient walls of Babylon that the Kassite conquerors established their headquarters; and it was to Babylon, long rebuilt and once more powerful, that the Pharaohs of the eighteenth Dynasty and the Hittite kings of Cappadocia addressed their diplomatic correspondence. During Assyria's long struggle with the southern kingdom Babylon was always the protagonist, and no raid by Aramean or Chaldean tribes ever succeeded in ousting her from that position. At the height of Assyrian power she continued to be the chief check upon that empire's expansion, and the vacillating policy of the Sargonids in their treatment of the city sufficiently testifies to the dominant _rôle_ she continued to play in politics. And when Nineveh had fallen, it was Babylon that took her place in a great part of Western Asia. This continued pre-eminence of a single city is in striking contrast to the ephemeral authority of earlier capitals, and it can only be explained by some radical change in the general conditions of the country. One fact stands out clearly: Babylon's geographical position must have endowed her during this period with a strategical and commercial importance which enabled her to survive the rudest shocks to her material prosperity. A glance at the map will show that the city lay in the north of Babylonia, just below the confluence of the two great rivers in their lower course. Built originally on the left bank of the Euphrates, she was protected by its stream from any sudden incursion of the desert tribes. At the same time she was in immediate contact with the broad expanse of alluvial plain to the south-east, intersected by its network of canals.