In the mean time, Cyrus went on with his conquests in the heart of Asia, and at length, in the course of a few years, he had completed his arrangements and preparations for the attack on Babylon. He advanced at the head of a large force to the vicinity of the city. The King of Babylon, whose name was Belshazzar, withdrew within the walls, shut the gates, and felt perfectly secure. A simple wall was in those days a very effectual protection against any armed force whatever, if it was only high enough not to be scaled, and thick enough to resist the blows of a battering ram. The artillery of modern times would have speedily made a fatal breach in such structures; but there was nothing but the simple force of man, applied through brazen-headed beams of wood, in those days, and Belshazzar knew well that his walls would bid all such modes of demolition a complete defiance. He stationed his soldiers, therefore, on the walls, and his sentinels in the watch towers, while he himself, and all the nobles of his court, feeling perfectly secure in their impregnable condition, and being abundantly supplied with all the means that the whole empire could furnish, both for sustenance and enjoyment, gave themselves up, in their spacious palaces and gardens, to gayety, festivity, and pleasure. Cyrus advanced to the city. He stationed one large detachment of his troops at the opening in the main walls where the river entered into the city, and another one below, where it issued from it. These detachments were ordered to march into the city by the bed of the river, as soon as they should observe the water subsiding. He then employed a vast force of laborers to open new channels, and to widen and deepen those which had existed before, for the purpose of drawing off the waters from their usual bed. When these passages were thus prepared, the water was let into them one night, at a time previously designated, and it soon ceased to flow through the city. The detachments of soldiers marched in over the bed of the stream, carrying with them vast numbers of ladders. With these they easily scaled the low walls which lined the banks of the river, and Belshazzar was thunderstruck with the announcement made to him in the midst of one of his feasts that the Persians were in complete and full possession of the city. CHAPTER IX. THE RESTORATION OF THE JEWS. B.C. 608