Under these circumstances Cyrus could only cross the Tigris from the east, and attempt an attack below the wall which united the two rivers. This was the line which, in fact, he followed. Berosus told us that Cyrus "marched from Persia against Nabonetus," and Herodotus exhibits him as occupied for a whole summer on the Diala. His occupation there, as Herodotus describes it, is very unintelligible; the Diala was punished by being divided into 360 canals, and so made fordable. That Cyrus should punish a river is both unlikely in itself and opposed to the religious conceptions of Iran, which as we know required the greatest respect to be paid to rivers; more improbable still and indeed impossible is it in the midst of the war against Babylon. If we do not assume that the source from which Herodotus drew has wrongly brought a great work of irrigation which Cyrus undertook for the land of the Diala at some other time into connection with this war against Babylon, it must be the passage of the Tigris which is in question. What we know of the military achievements of Cyrus does not allow us to suppose that when once in the field he would give his opponents the respite of a whole summer. If we could assume that the army of Nabonetus had contested the crossing with Cyrus at this point, above the mouth of the Diala, where at a later time the Babylonians attempted to check Darius--and that they had ships of war in the Tigris then, as at the time of Darius--we might then suppose that Cyrus reached the Tigris above the mouth of the Diala, and not being able to force the crossing, attempted to carry off the water of the river into the Diala, above and behind his camp, and at length succeeded in his attempt. Even then the number of the canals is very remarkable. But whether the supposition is right or wrong, in any case we may assume on the basis of the narrative of Herodotus that Cyrus began the war against Babylon in the spring of the year 539 B.C., that he crossed the Tigris in the neighbourhood of the Diala, and that the only result of his first campaign was to effect the passage of the Tigris and retain command of the river. From this point, in the next spring, he led his army, as Herodotus states, in a diagonal across Babylonia towards the city. Nabonetus lost the battle, which, as Herodotus says, was fought in the neighbourhood of Babylon. Of Nabonetus and his fate the historian says not a word; we have therefore no reason to doubt the statement of Berosus, that Nabonetus did not again return to Babylon, but took refuge in Borsippa with a few companions, and was there besieged. It was obviously of great advantage to Cyrus to prevent the Babylonians from entering into their city, to drive away the army or part of it from the city in order to diminish the number of those who could defend the walls. He might accomplish this object by strengthening his right wing and advancing with it. If