troops and form a combined army capable of striking an important blow. This was a cause of dangerous inferiority in a conflict with the Assyrians, the chief part of whose forces, bivouacking close to the capital during the winter months, could leave their quarters and set out on a campaign at little more than a day's notice; the kings of Elam minimised the danger by keeping sufficient troops under arms on their northern and western frontiers to meet any emergency, but an attack by sea seemed to them so unlikely that they had not, for a long time past, thought of protecting their coast-line. The ancient Chaldaean cities, Uru, Bagash, Uruk, and Bridu had possessed fleets on the Persian Gulf; but the times were long past when they used to send to procure stone and wood from the countries of Magan and Melukhkha, and the seas which they had ruled were now traversed only by merchant vessels or fishing-boats. Besides this, the condition of the estuary seemed to prohibit all attack from that side. The space between Bit-Yakin and the long line of dunes or mud-banks which blocked the entrance to it was not so much a gulf as a lagoon of uncertain and shifting extent; the water flowed only in the middle, being stagnant near the shores; the whole expanse was irregularly dotted over with mud-banks, and its service was constantly altered by the alluvial soil brought down by the Tigris, the Euphrates, the Ulai, and the Uknu. The navigation of this lagoon was dangerous, for the relative positions of the channels and shallows were constantly shifting, and vessels of deep draught often ran aground in passing from one end of it to the other.* * The condition I describe here is very similar to what Alexander's admirals found 350 years later. Arrian has preserved for us the account of Nearchus' navigation in these waters, and his description shows such a well-defined condition of the estuary that its main outline must have remained unchanged for a considerable time; the only subsequent alterations which had taken place must have been in the internal configuration, where the deposit of alluvium must have necessarily reduced the area of the lake since the time of Sennacherib. The little map on the next page has no pretension to scientific exactitude; its only object is to show roughly what the estuary of the Euphrates was like, and to illustrate approximately the course of the Assyrian expedition. [Illustration: 048.jpg MAP THE NAR-MARRATUM IN THE TIME OF SENNACHERIB] Sennacherib decided to march his force to the mouth of the Euphrates, and, embarking it there, to bring it to bear suddenly on the portion of Elamite territory nearest to Nagitu: if all went well, he would thus have time to crush the rising power of Merodach-baladan and regain his own port of departure before Khalludush could muster a sufficient army to render efficient succour to his vassal.