Of all the nations who had in turn occupied the plains of the Lower Euphrates and the marshes bordering on Arabia, the Kalda alone had retained their full vitality. They were constantly recruited by immigrants from their kinsfolk of the desert, and the continual infiltration of these semi-barbarous elements kept the race from becoming enervated by contact with the indigenous population, and more than compensated for the losses in their ranks occasioned by war. The invasion of Tiglath-pileser and the consequent deportations of prisoners had decimated the tribes of Bit-Shilani, Bit-Shaali, and Bit-Amuhkani, the principalities of the Kalda which lay nearest to Babylonian territory, and which had borne the brunt of attack in the preceding period; but their weakness brought into notice a power better equipped for warfare, whose situation in their rear had as a rule hitherto preserved it from contact with the Assyrians, namely, Bit-Yakin. The continual deposit of alluvial soil at the mouths of the rivers had greatly altered the coastline from the earliest historic times downwards. The ancient estuary was partly filled up, especially on the western side, where the Euphrates enters the Persian Gulf: a narrow barrier of sand and silt extended between the marshes of Arabia and Susiana, at the spot where the streams of fresh water met the tidal waters of the sea, and all that was left of the ancient gulf was a vast lagoon, or, as the dwellers on the banks called it, a kind of brackish river, _Nar marratum_. Bit-Yakin occupied the southern and western portions of this district, from the mouth of the Tigris to the edge of the desert. The aspect of the country was constantly changing, and presented no distinctive features; it was a region difficult to attack and easy to defend; it consisted first of a spongy plain, saturated with water, with scattered artificial mounds on which stood the clustered huts of the villages; between this plain and the shore stretched a labyrinth of fens and peat-bogs, irregularly divided by canals and channels freshly formed each year in flood-time, meres strewn with floating islets, immense reed-beds where the neighbouring peasants took refuge from attack, and into which no one would venture to penetrate without hiring some friendly native as a guide. In this fenland dwelt the Kalda in their low, small conical huts of reeds, somewhat resembling giant beehives, and in all respects similar to those which the Bedawin of Irak inhabit at the present day. [Illustration: 343.jpg ASSYRIAN SOLDIERS PURSUING KALDA REFUGEES IN A BED OF REEDS] Drawn by Faucher-Gudin, from a bas-relief reproduced in Layard.